138917636 has 24 divisors (see below), whose sum is σ = 285608064. Its totient is φ = 58286880.

The previous prime is 138917621. The next prime is 138917641. The reversal of 138917636 is 636719831.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120860 + ... + 122003.

It is an arithmetic number, because the mean of its divisors is an integer number (11900336).

Almost surely, 2^138917636 is an apocalyptic number.

It is an amenable number.

138917636 is an abundant number, since it is smaller than the sum of its proper divisors (146690428).

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

138917636 is a wasteful number, since it uses less digits than its factorization.

138917636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242891 (or 242889 counting only the distinct ones).

The product of its digits is 163296, while the sum is 44.

The square root of 138917636 is about 11786.3325933048. The cubic root of 138917636 is about 517.9078114441.

The spelling of 138917636 in words is "one hundred thirty-eight million, nine hundred seventeen thousand, six hundred thirty-six".