Base | Representation |
---|---|
bin | 100110011100… |
… | …1010100100011 |
3 | 1101221010012122 |
4 | 1030321110203 |
5 | 20130021411 |
6 | 2000014455 |
7 | 333223616 |
oct | 114712443 |
9 | 41833178 |
10 | 20157731 |
11 | 10418890 |
12 | 690142b |
13 | 423a169 |
14 | 296a17d |
15 | 1b829db |
hex | 1339523 |
20157731 has 8 divisors (see below), whose sum is σ = 22186224. Its totient is φ = 18161920.
The previous prime is 20157707. The next prime is 20157737. The reversal of 20157731 is 13775102.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a cyclic number.
It is not a de Polignac number, because 20157731 - 218 = 19895587 is a prime.
It is a super-2 number, since 2×201577312 = 812668238136722, which contains 22 as substring.
It is a Duffinian number.
It is a self number, because there is not a number n which added to its sum of digits gives 20157731.
It is not an unprimeable number, because it can be changed into a prime (20157737) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6866 + ... + 9351.
It is an arithmetic number, because the mean of its divisors is an integer number (2773278).
Almost surely, 220157731 is an apocalyptic number.
20157731 is a deficient number, since it is larger than the sum of its proper divisors (2028493).
20157731 is a wasteful number, since it uses less digits than its factorization.
20157731 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 16341.
The product of its (nonzero) digits is 1470, while the sum is 26.
The square root of 20157731 is about 4489.7361837863. The cubic root of 20157731 is about 272.1534736168.
It can be divided in two parts, 20 and 157731, that added together give a palindrome (157751).
The spelling of 20157731 in words is "twenty million, one hundred fifty-seven thousand, seven hundred thirty-one".
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