138635945 has 24 divisors (see below), whose sum is σ = 194059008. Its totient is φ = 94802400.

The previous prime is 138635911. The next prime is 138635957. The reversal of 138635945 is 549536831.

It is not a de Polignac number, because 138635945 - 2¹⁰ = 138634921 is a prime.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138635896 and 138635905.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 139400 + ... + 140390.

It is an arithmetic number, because the mean of its divisors is an integer number (8085792).

Almost surely, 2^138635945 is an apocalyptic number.

It is an amenable number.

138635945 is a deficient number, since it is larger than the sum of its proper divisors (55423063).

138635945 is an equidigital number, since it uses as much as digits as its factorization.

138635945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1581 (or 1574 counting only the distinct ones).

The product of its digits is 388800, while the sum is 44.

The square root of 138635945 is about 11774.3766289345. The cubic root of 138635945 is about 517.5575110923.

The spelling of 138635945 in words is "one hundred thirty-eight million, six hundred thirty-five thousand, nine hundred forty-five".