172555681 has 2 divisors, whose sum is σ = 172555682. Its totient is φ = 172555680.

The previous prime is 172555673. The next prime is 172555687. The reversal of 172555681 is 186555271.

It is a happy number.

172555681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91393600 + 81162081 = 9560^2 + 9009^2 .

It is a cyclic number.

It is not a de Polignac number, because 172555681 - 2³ = 172555673 is a prime.

It is a super-2 number, since 2×172555681² = 59550926090747522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (172555687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86277840 + 86277841.

It is an arithmetic number, because the mean of its divisors is an integer number (86277841).

Almost surely, 2^172555681 is an apocalyptic number.

It is an amenable number.

172555681 is a deficient number, since it is larger than the sum of its proper divisors (1).

172555681 is an equidigital number, since it uses as much as digits as its factorization.

172555681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84000, while the sum is 40.

The square root of 172555681 is about 13136.0451049774. The cubic root of 172555681 is about 556.7280296577.

The spelling of 172555681 in words is "one hundred seventy-two million, five hundred fifty-five thousand, six hundred eighty-one".