| Base | Representation |
|---|---|
| bin | 10000100000001… |
| … | …10100001000000 |
| 3 | 100122111102020000 |
| 4 | 20100012201000 |
| 5 | 240420014340 |
| 6 | 21423120000 |
| 7 | 3300465300 |
| oct | 1020064100 |
| 9 | 318442200 |
| 10 | 138438720 |
| 11 | 71166072 |
| 12 | 3a443000 |
| 13 | 228b1804 |
| 14 | 14559600 |
| 15 | c248d30 |
| hex | 8406840 |
138438720 has 420 divisors, whose sum is σ = 578106540. Its totient is φ = 31352832.
The previous prime is 138438697. The next prime is 138438743. The reversal of 138438720 is 27834831.
It is an interprime number because it is at equal distance from previous prime (138438697) and next prime (138438743).
It can be written as a sum of positive squares in 2 ways, for example, as 73410624 + 65028096 = 8568^2 + 8064^2 .
It is a tau number, because it is divible by the number of its divisors (420).
It is a Harshad number since it is a multiple of its sum of digits (36).
It is an unprimeable number.
It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1270026 + ... + 1270134.
Almost surely, 2138438720 is an apocalyptic number.
138438720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 138438720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (289053270).
138438720 is an abundant number, since it is smaller than the sum of its proper divisors (439667820).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
138438720 is a wasteful number, since it uses less digits than its factorization.
138438720 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 152 (or 126 counting only the distinct ones).
The product of its (nonzero) digits is 32256, while the sum is 36.
The square root of 138438720 is about 11765.9984701682. The cubic root of 138438720 is about 517.3119669734.
Adding to 138438720 its sum of digits (36), we get a square (138438756 = 117662).
It can be divided in two parts, 1384 and 38720, that added together give a palindrome (40104).
The spelling of 138438720 in words is "one hundred thirty-eight million, four hundred thirty-eight thousand, seven hundred twenty".
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