31320999973 has 2 divisors, whose sum is σ = 31320999974. Its totient is φ = 31320999972.

The previous prime is 31320999923. The next prime is 31321000001. The reversal of 31320999973 is 37999902313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28304024644 + 3016975329 = 168238^2 + 54927^2 .

It is a cyclic number.

It is not a de Polignac number, because 31320999973 - 2¹³ = 31320991781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31320999923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15660499986 + 15660499987.

It is an arithmetic number, because the mean of its divisors is an integer number (15660499987).

Almost surely, 2^31320999973 is an apocalyptic number.

It is an amenable number.

31320999973 is a deficient number, since it is larger than the sum of its proper divisors (1).

31320999973 is an equidigital number, since it uses as much as digits as its factorization.

31320999973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2480058, while the sum is 55.

The spelling of 31320999973 in words is "thirty-one billion, three hundred twenty million, nine hundred ninety-nine thousand, nine hundred seventy-three".