139568635921 has 12 divisors (see below), whose sum is σ = 165210936436. Its totient is φ = 117120532320.

The previous prime is 139568635889. The next prime is 139568635957. The reversal of 139568635921 is 129536865931.

It can be written as a sum of positive squares in 2 ways, for example, as 15935527696 + 123633108225 = 126236^2 + 351615^2 .

It is not a de Polignac number, because 139568635921 - 2⁵ = 139568635889 is a prime.

It is a hoax number, since the sum of its digits (58) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (139568635961) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44362266 + ... + 44365411.

Almost surely, 2^139568635921 is an apocalyptic number.

139568635921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

139568635921 is a deficient number, since it is larger than the sum of its proper divisors (25642300515).

139568635921 is a wasteful number, since it uses less digits than its factorization.

139568635921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88727712 (or 88727701 counting only the distinct ones).

The product of its digits is 10497600, while the sum is 58.

The spelling of 139568635921 in words is "one hundred thirty-nine billion, five hundred sixty-eight million, six hundred thirty-five thousand, nine hundred twenty-one".