28020831 has 16 divisors (see below), whose sum is σ = 39526656. Its totient is φ = 17620416.

The previous prime is 28020827. The next prime is 28020847. The reversal of 28020831 is 13802082.

It is not a de Polignac number, because 28020831 - 2² = 28020827 is a prime.

It is a super-2 number, since 2×28020831² = 1570333939861122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28020331) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2256 + ... + 7818.

It is an arithmetic number, because the mean of its divisors is an integer number (2470416).

Almost surely, 2^28020831 is an apocalyptic number.

28020831 is a deficient number, since it is larger than the sum of its proper divisors (11505825).

28020831 is a wasteful number, since it uses less digits than its factorization.

28020831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5662.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 28020831 is about 5293.4706006551. The cubic root of 28020831 is about 303.7341823124.

The spelling of 28020831 in words is "twenty-eight million, twenty thousand, eight hundred thirty-one".