138221832 has 64 divisors (see below), whose sum is σ = 418158720. Its totient is φ = 37168128.

The previous prime is 138221819. The next prime is 138221857. The reversal of 138221832 is 238122831.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 138221832.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21343 + ... + 27054.

It is an arithmetic number, because the mean of its divisors is an integer number (6533730).

Almost surely, 2^138221832 is an apocalyptic number.

138221832 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

138221832 is an abundant number, since it is smaller than the sum of its proper divisors (279936888).

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

138221832 is a wasteful number, since it uses less digits than its factorization.

138221832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48430 (or 48426 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 138221832 is about 11756.7781300831. The cubic root of 138221832 is about 517.0416731283.

Subtracting 138221832 from its reverse (238122831), we obtain a palindrome (99900999).

The spelling of 138221832 in words is "one hundred thirty-eight million, two hundred twenty-one thousand, eight hundred thirty-two".