172823939 has 4 divisors (see below), whose sum is σ = 174439224. Its totient is φ = 171208656.

The previous prime is 172823927. The next prime is 172823947. The reversal of 172823939 is 939328271.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-172823939 is a prime.

It is a super-2 number, since 2×172823939² = 59736227782951442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 172823939.

It is not an unprimeable number, because it can be changed into a prime (172823039) 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, 807482 + ... + 807695.

It is an arithmetic number, because the mean of its divisors is an integer number (43609806).

Almost surely, 2^172823939 is an apocalyptic number.

172823939 is a deficient number, since it is larger than the sum of its proper divisors (1615285).

172823939 is a wasteful number, since it uses less digits than its factorization.

172823939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615284.

The product of its digits is 163296, while the sum is 44.

The square root of 172823939 is about 13146.2518993057. The cubic root of 172823939 is about 557.0163799095.

The spelling of 172823939 in words is "one hundred seventy-two million, eight hundred twenty-three thousand, nine hundred thirty-nine".