172972871 has 2 divisors, whose sum is σ = 172972872. Its totient is φ = 172972870.

The previous prime is 172972859. The next prime is 172972879. The reversal of 172972871 is 178279271.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172972871 is a prime.

It is a super-2 number, since 2×172972871² = 59839228203965282, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172972879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86486435 + 86486436.

It is an arithmetic number, because the mean of its divisors is an integer number (86486436).

Almost surely, 2^172972871 is an apocalyptic number.

172972871 is a deficient number, since it is larger than the sum of its proper divisors (1).

172972871 is an equidigital number, since it uses as much as digits as its factorization.

172972871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 98784, while the sum is 44.

The square root of 172972871 is about 13151.9151076944. The cubic root of 172972871 is about 557.1763379679.

The spelling of 172972871 in words is "one hundred seventy-two million, nine hundred seventy-two thousand, eight hundred seventy-one".