31115121157 has 2 divisors, whose sum is σ = 31115121158. Its totient is φ = 31115121156.

The previous prime is 31115121151. The next prime is 31115121181. The reversal of 31115121157 is 75112151113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28976891076 + 2138230081 = 170226^2 + 46241^2 .

It is a cyclic number.

It is not a de Polignac number, because 31115121157 - 2¹⁹ = 31114596869 is a prime.

It is a super-2 number, since 2×31115121157² (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 (31115121151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15557560578 + 15557560579.

It is an arithmetic number, because the mean of its divisors is an integer number (15557560579).

Almost surely, 2^31115121157 is an apocalyptic number.

It is an amenable number.

31115121157 is a deficient number, since it is larger than the sum of its proper divisors (1).

31115121157 is an equidigital number, since it uses as much as digits as its factorization.

31115121157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1050, while the sum is 28.

The spelling of 31115121157 in words is "thirty-one billion, one hundred fifteen million, one hundred twenty-one thousand, one hundred fifty-seven".