172639 has 4 divisors (see below), whose sum is σ = 178240. Its totient is φ = 167040.

The previous prime is 172633. The next prime is 172643. The reversal of 172639 is 936271.

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

It is a cyclic number.

It is not a de Polignac number, because 172639 - 2⁵ = 172607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172633) 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, 2754 + ... + 2815.

It is an arithmetic number, because the mean of its divisors is an integer number (44560).

2¹⁷²⁶³⁹ is an apocalyptic number.

172639 is a deficient number, since it is larger than the sum of its proper divisors (5601).

172639 is an equidigital number, since it uses as much as digits as its factorization.

172639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5600.

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

The square root of 172639 is about 415.4984957855. The cubic root of 172639 is about 55.6817621142.

The spelling of 172639 in words is "one hundred seventy-two thousand, six hundred thirty-nine".