28820631 has 8 divisors (see below), whose sum is σ = 43917184. Its totient is φ = 16468920.

The previous prime is 28820629. The next prime is 28820639. The reversal of 28820631 is 13602882.

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

It is not a de Polignac number, because 28820631 - 2¹ = 28820629 is a prime.

It is a super-2 number, since 2×28820631² = 1661257542476322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28820639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 686185 + ... + 686226.

It is an arithmetic number, because the mean of its divisors is an integer number (5489648).

Almost surely, 2^28820631 is an apocalyptic number.

28820631 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28820631 is a deficient number, since it is larger than the sum of its proper divisors (15096553).

28820631 is a wasteful number, since it uses less digits than its factorization.

28820631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1372421.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 28820631 is about 5368.4849818175. The cubic root of 28820631 is about 306.5969486809.

The spelling of 28820631 in words is "twenty-eight million, eight hundred twenty thousand, six hundred thirty-one".