31312123009 has 2 divisors, whose sum is σ = 31312123010. Its totient is φ = 31312123008.

The previous prime is 31312122977. The next prime is 31312123033. The reversal of 31312123009 is 90032121313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16827278400 + 14484844609 = 129720^2 + 120353^2 .

It is a cyclic number.

It is not a de Polignac number, because 31312123009 - 2⁵ = 31312122977 is a prime.

It is not a weakly prime, because it can be changed into another prime (31312124009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656061504 + 15656061505.

It is an arithmetic number, because the mean of its divisors is an integer number (15656061505).

Almost surely, 2^31312123009 is an apocalyptic number.

It is an amenable number.

31312123009 is a deficient number, since it is larger than the sum of its proper divisors (1).

31312123009 is an equidigital number, since it uses as much as digits as its factorization.

31312123009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 25.

The spelling of 31312123009 in words is "thirty-one billion, three hundred twelve million, one hundred twenty-three thousand, nine".