31537852921 has 3 divisors (see below), whose sum is σ = 31538030511. Its totient is φ = 31537675332.

The previous prime is 31537852897. The next prime is 31537852967. The reversal of 31537852921 is 12925873513.

The square root of 31537852921 is 177589.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 3655532521 + 27882320400 = 60461^2 + 166980^2 .

It is not a de Polignac number, because 31537852921 - 2²³ = 31529464313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31537852421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 88795 + ... + 266383.

It is an arithmetic number, because the mean of its divisors is an integer number (10512676837).

Almost surely, 2^31537852921 is an apocalyptic number.

31537852921 is the 177589-th square number.

31537852921 is the 88795-th centered octagonal number.

It is an amenable number.

31537852921 is a deficient number, since it is larger than the sum of its proper divisors (177590).

31537852921 is an frugal number, since it uses more digits than its factorization.

31537852921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355178 (or 177589 counting only the distinct ones).

The product of its digits is 453600, while the sum is 46.

The spelling of 31537852921 in words is "thirty-one billion, five hundred thirty-seven million, eight hundred fifty-two thousand, nine hundred twenty-one".