138655816 has 32 divisors (see below), whose sum is σ = 283368960. Its totient is φ = 63220032.

The previous prime is 138655813. The next prime is 138655817. The reversal of 138655816 is 618556831.

It is not an unprimeable number, because it can be changed into a prime (138655813) 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, 601 + ... + 16663.

It is an arithmetic number, because the mean of its divisors is an integer number (8855280).

Almost surely, 2^138655816 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138655816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141684480).

138655816 is an abundant number, since it is smaller than the sum of its proper divisors (144713144).

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

138655816 is a wasteful number, since it uses less digits than its factorization.

138655816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16165 (or 16161 counting only the distinct ones).

The product of its digits is 172800, while the sum is 43.

The square root of 138655816 is about 11775.2204225653. The cubic root of 138655816 is about 517.5822374694.

The spelling of 138655816 in words is "one hundred thirty-eight million, six hundred fifty-five thousand, eight hundred sixteen".