31504681973 has 2 divisors, whose sum is σ = 31504681974. Its totient is φ = 31504681972.

The previous prime is 31504681951. The next prime is 31504681981. The reversal of 31504681973 is 37918640513.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19790299684 + 11714382289 = 140678^2 + 108233^2 .

It is a cyclic number.

It is not a de Polignac number, because 31504681973 - 2⁶ = 31504681909 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31504681073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15752340986 + 15752340987.

It is an arithmetic number, because the mean of its divisors is an integer number (15752340987).

Almost surely, 2^31504681973 is an apocalyptic number.

It is an amenable number.

31504681973 is a deficient number, since it is larger than the sum of its proper divisors (1).

31504681973 is an equidigital number, since it uses as much as digits as its factorization.

31504681973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 544320, while the sum is 47.

The spelling of 31504681973 in words is "thirty-one billion, five hundred four million, six hundred eighty-one thousand, nine hundred seventy-three".