318081557 has 2 divisors, whose sum is σ = 318081558. Its totient is φ = 318081556.

The previous prime is 318081521. The next prime is 318081583. The reversal of 318081557 is 755180813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 316341796 + 1739761 = 17786^2 + 1319^2 .

It is a cyclic number.

It is not a de Polignac number, because 318081557 - 2⁸ = 318081301 is a prime.

It is a super-4 number, since 4×318081557⁴ (a number of 35 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 318081557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (318081457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159040778 + 159040779.

It is an arithmetic number, because the mean of its divisors is an integer number (159040779).

Almost surely, 2^318081557 is an apocalyptic number.

It is an amenable number.

318081557 is a deficient number, since it is larger than the sum of its proper divisors (1).

318081557 is an equidigital number, since it uses as much as digits as its factorization.

318081557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 33600, while the sum is 38.

The square root of 318081557 is about 17834.8410982548. The cubic root of 318081557 is about 682.6207666001.

The spelling of 318081557 in words is "three hundred eighteen million, eighty-one thousand, five hundred fifty-seven".