138161520 has 240 divisors, whose sum is σ = 538536960. Its totient is φ = 31090176.

The previous prime is 138161501. The next prime is 138161531. The reversal of 138161520 is 25161831.

138161520 is a `hidden beast` number, since 1 + 3 + 81 + 61 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 397987 + ... + 398333.

It is an arithmetic number, because the mean of its divisors is an integer number (2243904).

Almost surely, 2^138161520 is an apocalyptic number.

138161520 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 138161520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269268480).

138161520 is an abundant number, since it is smaller than the sum of its proper divisors (400375440).

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

138161520 is a wasteful number, since it uses less digits than its factorization.

138161520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452 (or 443 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 138161520 is about 11754.2128617785. The cubic root of 138161520 is about 516.9664598434.

The spelling of 138161520 in words is "one hundred thirty-eight million, one hundred sixty-one thousand, five hundred twenty".