872391 has 8 divisors (see below), whose sum is σ = 1252720. Its totient is φ = 536832.

The previous prime is 872387. The next prime is 872393. The reversal of 872391 is 193278.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 872391 - 2² = 872387 is a prime.

It is a super-2 number, since 2×872391² = 1522132113762, which contains 22 as substring.

It is a Duffinian number.

872391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (872393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11146 + ... + 11223.

It is an arithmetic number, because the mean of its divisors is an integer number (156590).

2⁸⁷²³⁹¹ is an apocalyptic number.

872391 is a deficient number, since it is larger than the sum of its proper divisors (380329).

872391 is a wasteful number, since it uses less digits than its factorization.

872391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22385.

The product of its digits is 3024, while the sum is 30.

The square root of 872391 is about 934.0187364288. The cubic root of 872391 is about 95.5514009271.

The spelling of 872391 in words is "eight hundred seventy-two thousand, three hundred ninety-one".