172871857 has 2 divisors, whose sum is σ = 172871858. Its totient is φ = 172871856.

The previous prime is 172871791. The next prime is 172871869. The reversal of 172871857 is 758178271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161010721 + 11861136 = 12689^2 + 3444^2 .

It is a cyclic number.

It is not a de Polignac number, because 172871857 - 2⁷ = 172871729 is a prime.

It is not a weakly prime, because it can be changed into another prime (172877857) 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, 86435928 + 86435929.

It is an arithmetic number, because the mean of its divisors is an integer number (86435929).

Almost surely, 2^172871857 is an apocalyptic number.

It is an amenable number.

172871857 is a deficient number, since it is larger than the sum of its proper divisors (1).

172871857 is an equidigital number, since it uses as much as digits as its factorization.

172871857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 219520, while the sum is 46.

The square root of 172871857 is about 13148.0742696412. The cubic root of 172871857 is about 557.0678555029.

The spelling of 172871857 in words is "one hundred seventy-two million, eight hundred seventy-one thousand, eight hundred fifty-seven".