31207993 has 2 divisors, whose sum is σ = 31207994. Its totient is φ = 31207992.

The previous prime is 31207961. The next prime is 31208003. The reversal of 31207993 is 39970213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24720784 + 6487209 = 4972^2 + 2547^2 .

It is a cyclic number.

It is not a de Polignac number, because 31207993 - 2⁵ = 31207961 is a prime.

It is not a weakly prime, because it can be changed into another prime (31204993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15603996 + 15603997.

It is an arithmetic number, because the mean of its divisors is an integer number (15603997).

Almost surely, 2^31207993 is an apocalyptic number.

It is an amenable number.

31207993 is a deficient number, since it is larger than the sum of its proper divisors (1).

31207993 is an equidigital number, since it uses as much as digits as its factorization.

31207993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 31207993 is about 5586.4114599625. The cubic root of 31207993 is about 314.8390645115.

The spelling of 31207993 in words is "thirty-one million, two hundred seven thousand, nine hundred ninety-three".