31312021373 has 2 divisors, whose sum is σ = 31312021374. Its totient is φ = 31312021372.

The previous prime is 31312021309. The next prime is 31312021381. The reversal of 31312021373 is 37312021313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31214762329 + 97259044 = 176677^2 + 9862^2 .

It is a cyclic number.

It is not a de Polignac number, because 31312021373 - 2⁶ = 31312021309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31312021673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656010686 + 15656010687.

It is an arithmetic number, because the mean of its divisors is an integer number (15656010687).

Almost surely, 2^31312021373 is an apocalyptic number.

It is an amenable number.

31312021373 is a deficient number, since it is larger than the sum of its proper divisors (1).

31312021373 is an equidigital number, since it uses as much as digits as its factorization.

31312021373 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2268, while the sum is 26.

Adding to 31312021373 its reverse (37312021313), we get a palindrome (68624042686).

The spelling of 31312021373 in words is "thirty-one billion, three hundred twelve million, twenty-one thousand, three hundred seventy-three".