31123323157 has 2 divisors, whose sum is σ = 31123323158. Its totient is φ = 31123323156.

The previous prime is 31123323031. The next prime is 31123323167. The reversal of 31123323157 is 75132332113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30905288401 + 218034756 = 175799^2 + 14766^2 .

It is a cyclic number.

It is not a de Polignac number, because 31123323157 - 2⁷ = 31123323029 is a prime.

It is a super-2 number, since 2×31123323157² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31123323167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15561661578 + 15561661579.

It is an arithmetic number, because the mean of its divisors is an integer number (15561661579).

Almost surely, 2^31123323157 is an apocalyptic number.

It is an amenable number.

31123323157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31123323157 is an equidigital number, since it uses as much as digits as its factorization.

31123323157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 31.

The spelling of 31123323157 in words is "thirty-one billion, one hundred twenty-three million, three hundred twenty-three thousand, one hundred fifty-seven".