31312120109 has 2 divisors, whose sum is σ = 31312120110. Its totient is φ = 31312120108.

The previous prime is 31312120039. The next prime is 31312120141. The reversal of 31312120109 is 90102121313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20893835209 + 10418284900 = 144547^2 + 102070^2 .

It is a cyclic number.

It is not a de Polignac number, because 31312120109 - 2²⁸ = 31043684653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31312120909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656060054 + 15656060055.

It is an arithmetic number, because the mean of its divisors is an integer number (15656060055).

Almost surely, 2^31312120109 is an apocalyptic number.

It is an amenable number.

31312120109 is a deficient number, since it is larger than the sum of its proper divisors (1).

31312120109 is an equidigital number, since it uses as much as digits as its factorization.

31312120109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 23.

The spelling of 31312120109 in words is "thirty-one billion, three hundred twelve million, one hundred twenty thousand, one hundred nine".