138521394 has 32 divisors (see below), whose sum is σ = 335810880. Its totient is φ = 41976000.

The previous prime is 138521363. The next prime is 138521437. The reversal of 138521394 is 493125831.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116007 + ... + 117194.

It is an arithmetic number, because the mean of its divisors is an integer number (10494090).

Almost surely, 2^138521394 is an apocalyptic number.

138521394 is an abundant number, since it is smaller than the sum of its proper divisors (197289486).

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

138521394 is a wasteful number, since it uses less digits than its factorization.

138521394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233223 (or 233217 counting only the distinct ones).

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

The square root of 138521394 is about 11769.5112048037. The cubic root of 138521394 is about 517.4149240527.

The spelling of 138521394 in words is "one hundred thirty-eight million, five hundred twenty-one thousand, three hundred ninety-four".