31988555321 has 4 divisors (see below), whose sum is σ = 32125845492. Its totient is φ = 31851265152.

The previous prime is 31988555303. The next prime is 31988555329. The reversal of 31988555321 is 12355588913.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22811873296 + 9176682025 = 151036^2 + 95795^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31988555321 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31988555321.

It is not an unprimeable number, because it can be changed into a prime (31988555329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68644736 + ... + 68645201.

It is an arithmetic number, because the mean of its divisors is an integer number (8031461373).

Almost surely, 2^31988555321 is an apocalyptic number.

It is an amenable number.

31988555321 is a deficient number, since it is larger than the sum of its proper divisors (137290171).

31988555321 is a wasteful number, since it uses less digits than its factorization.

31988555321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137290170.

The product of its digits is 1296000, while the sum is 50.

The spelling of 31988555321 in words is "thirty-one billion, nine hundred eighty-eight million, five hundred fifty-five thousand, three hundred twenty-one".