31720761925 has 6 divisors (see below), whose sum is σ = 39333744818. Its totient is φ = 25376609520.

The previous prime is 31720761913. The next prime is 31720761929. The reversal of 31720761925 is 52916702713.

It can be written as a sum of positive squares in 3 ways, for example, as 1849516036 + 29871245889 = 43006^2 + 172833^2 .

It is not a de Polignac number, because 31720761925 - 2²¹ = 31718664773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31720761929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 634415214 + ... + 634415263.

Almost surely, 2^31720761925 is an apocalyptic number.

It is an amenable number.

31720761925 is a deficient number, since it is larger than the sum of its proper divisors (7612982893).

31720761925 is a wasteful number, since it uses less digits than its factorization.

31720761925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1268830487 (or 1268830482 counting only the distinct ones).

The product of its (nonzero) digits is 158760, while the sum is 43.

The spelling of 31720761925 in words is "thirty-one billion, seven hundred twenty million, seven hundred sixty-one thousand, nine hundred twenty-five".