172878631 has 2 divisors, whose sum is σ = 172878632. Its totient is φ = 172878630.

The previous prime is 172878617. The next prime is 172878637. The reversal of 172878631 is 136878271.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 172878631 - 2⁹ = 172878119 is a prime.

It is a super-2 number, since 2×172878631² = 59774042112868322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172878637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86439315 + 86439316.

It is an arithmetic number, because the mean of its divisors is an integer number (86439316).

Almost surely, 2^172878631 is an apocalyptic number.

172878631 is a deficient number, since it is larger than the sum of its proper divisors (1).

172878631 is an equidigital number, since it uses as much as digits as its factorization.

172878631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 112896, while the sum is 43.

The square root of 172878631 is about 13148.3318713820. The cubic root of 172878631 is about 557.0751316600.

The spelling of 172878631 in words is "one hundred seventy-two million, eight hundred seventy-eight thousand, six hundred thirty-one".