138156660 has 36 divisors (see below), whose sum is σ = 419075748. Its totient is φ = 36841728.

The previous prime is 138156659. The next prime is 138156713. The reversal of 138156660 is 66651831.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 49871844 + 88284816 = 7062^2 + 9396^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 383589 + ... + 383948.

It is an arithmetic number, because the mean of its divisors is an integer number (11640993).

Almost surely, 2^138156660 is an apocalyptic number.

138156660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138156660 is an abundant number, since it is smaller than the sum of its proper divisors (280919088).

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

138156660 is a wasteful number, since it uses less digits than its factorization.

138156660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767552 (or 767547 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 138156660 is about 11754.0061255727. The cubic root of 138156660 is about 516.9603981304.

The spelling of 138156660 in words is "one hundred thirty-eight million, one hundred fifty-six thousand, six hundred sixty".