172168518857 has 2 divisors, whose sum is σ = 172168518858. Its totient is φ = 172168518856.

The previous prime is 172168518817. The next prime is 172168518877. The reversal of 172168518857 is 758815861271.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 170749941961 + 1418576896 = 413219^2 + 37664^2 .

It is a cyclic number.

It is not a de Polignac number, because 172168518857 - 2¹⁸ = 172168256713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 172168518796 and 172168518805.

It is not a weakly prime, because it can be changed into another prime (172168518817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86084259428 + 86084259429.

It is an arithmetic number, because the mean of its divisors is an integer number (86084259429).

Almost surely, 2^172168518857 is an apocalyptic number.

It is an amenable number.

172168518857 is a deficient number, since it is larger than the sum of its proper divisors (1).

172168518857 is an equidigital number, since it uses as much as digits as its factorization.

172168518857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7526400, while the sum is 59.

The spelling of 172168518857 in words is "one hundred seventy-two billion, one hundred sixty-eight million, five hundred eighteen thousand, eight hundred fifty-seven".