172531 has 4 divisors (see below), whose sum is σ = 177232. Its totient is φ = 167832.

The previous prime is 172519. The next prime is 172541. The reversal of 172531 is 135271.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 172531 - 2¹¹ = 170483 is a prime.

It is a super-2 number, since 2×172531² = 59533891922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 172499 and 172508.

It is not an unprimeable number, because it can be changed into a prime (172541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2295 + ... + 2368.

It is an arithmetic number, because the mean of its divisors is an integer number (44308).

2¹⁷²⁵³¹ is an apocalyptic number.

172531 is a deficient number, since it is larger than the sum of its proper divisors (4701).

172531 is an equidigital number, since it uses as much as digits as its factorization.

172531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4700.

The product of its digits is 210, while the sum is 19.

The square root of 172531 is about 415.3685110838. The cubic root of 172531 is about 55.6701485067.

It can be divided in two parts, 172 and 531, that added together give a triangular number (703 = T₃₇).

The spelling of 172531 in words is "one hundred seventy-two thousand, five hundred thirty-one".