172309231 has 2 divisors, whose sum is σ = 172309232. Its totient is φ = 172309230.

The previous prime is 172309223. The next prime is 172309237. The reversal of 172309231 is 132903271.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 172309231 - 2³ = 172309223 is a prime.

It is a super-2 number, since 2×172309231² = 59380942175622722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 172309231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172309237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86154615 + 86154616.

It is an arithmetic number, because the mean of its divisors is an integer number (86154616).

Almost surely, 2^172309231 is an apocalyptic number.

172309231 is a deficient number, since it is larger than the sum of its proper divisors (1).

172309231 is an equidigital number, since it uses as much as digits as its factorization.

172309231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 172309231 is about 13126.6610758410. The cubic root of 172309231 is about 556.4628572901.

The spelling of 172309231 in words is "one hundred seventy-two million, three hundred nine thousand, two hundred thirty-one".