28379831 has 4 divisors (see below), whose sum is σ = 29072064. Its totient is φ = 27687600.

The previous prime is 28379809. The next prime is 28379833. The reversal of 28379831 is 13897382.

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 28379831 - 2²² = 24185527 is a prime.

It is a super-2 number, since 2×28379831² = 1610829615177122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 692191 = 28379831 / (2 + 8 + 3 + 7 + 9 + 8 + 3 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28379833) 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 3 ways as a sum of consecutive naturals, for example, 346055 + ... + 346136.

It is an arithmetic number, because the mean of its divisors is an integer number (7268016).

Almost surely, 2^28379831 is an apocalyptic number.

28379831 is a deficient number, since it is larger than the sum of its proper divisors (692233).

28379831 is an equidigital number, since it uses as much as digits as its factorization.

28379831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692232.

The product of its digits is 72576, while the sum is 41.

The square root of 28379831 is about 5327.2723789947. The cubic root of 28379831 is about 305.0258188302.

The spelling of 28379831 in words is "twenty-eight million, three hundred seventy-nine thousand, eight hundred thirty-one".