139521988 has 6 divisors (see below), whose sum is σ = 244163486. Its totient is φ = 69760992.

The previous prime is 139521953. The next prime is 139521989. The reversal of 139521988 is 889125931.

It can be written as a sum of positive squares in only one way, i.e., 101969604 + 37552384 = 10098^2 + 6128^2 .

It is not an unprimeable number, because it can be changed into a prime (139521989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 17440245 + ... + 17440252.

Almost surely, 2^139521988 is an apocalyptic number.

It is an amenable number.

139521988 is a deficient number, since it is larger than the sum of its proper divisors (104641498).

139521988 is a wasteful number, since it uses less digits than its factorization.

139521988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34880501 (or 34880499 counting only the distinct ones).

The product of its digits is 155520, while the sum is 46.

The square root of 139521988 is about 11811.9426006055. The cubic root of 139521988 is about 518.6577661924.

The spelling of 139521988 in words is "one hundred thirty-nine million, five hundred twenty-one thousand, nine hundred eighty-eight".