138570240 has 80 divisors (see below), whose sum is σ = 443016288. Its totient is φ = 36950016.

The previous prime is 138570233. The next prime is 138570251. The reversal of 138570240 is 42075831.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×138570240² = 38403422827315200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 138570198 and 138570207.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1342 + ... + 16701.

Almost surely, 2^138570240 is an apocalyptic number.

138570240 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 138570240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221508144).

138570240 is an abundant number, since it is smaller than the sum of its proper divisors (304446048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138570240 is an equidigital number, since it uses as much as digits as its factorization.

138570240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18069 (or 18053 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 138570240 is about 11771.5861293200. The cubic root of 138570240 is about 517.4757345853.

The spelling of 138570240 in words is "one hundred thirty-eight million, five hundred seventy thousand, two hundred forty".