68171557 has 2 divisors, whose sum is σ = 68171558. Its totient is φ = 68171556.

The previous prime is 68171507. The next prime is 68171567. The reversal of 68171557 is 75517186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66080641 + 2090916 = 8129^2 + 1446^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68171557 is a prime.

It is a super-2 number, since 2×68171557² = 9294722367608498, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68171507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34085778 + 34085779.

It is an arithmetic number, because the mean of its divisors is an integer number (34085779).

Almost surely, 2^68171557 is an apocalyptic number.

It is an amenable number.

68171557 is a deficient number, since it is larger than the sum of its proper divisors (1).

68171557 is an equidigital number, since it uses as much as digits as its factorization.

68171557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58800, while the sum is 40.

The square root of 68171557 is about 8256.6068696529. The cubic root of 68171557 is about 408.5084751199.

The spelling of 68171557 in words is "sixty-eight million, one hundred seventy-one thousand, five hundred fifty-seven".