157391917 has 2 divisors, whose sum is σ = 157391918. Its totient is φ = 157391916.

The previous prime is 157391887. The next prime is 157391939. The reversal of 157391917 is 719193751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94887081 + 62504836 = 9741^2 + 7906^2 .

It is a cyclic number.

It is not a de Polignac number, because 157391917 - 2²⁷ = 23174189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157391957) 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, 78695958 + 78695959.

It is an arithmetic number, because the mean of its divisors is an integer number (78695959).

Almost surely, 2^157391917 is an apocalyptic number.

It is an amenable number.

157391917 is a deficient number, since it is larger than the sum of its proper divisors (1).

157391917 is an equidigital number, since it uses as much as digits as its factorization.

157391917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 59535, while the sum is 43.

The square root of 157391917 is about 12545.5935292038. The cubic root of 157391917 is about 539.9175880178.

It can be divided in two parts, 1573 and 91917, that multiplied together give a palindrome (144585441).

The spelling of 157391917 in words is "one hundred fifty-seven million, three hundred ninety-one thousand, nine hundred seventeen".