28913631 has 16 divisors (see below), whose sum is σ = 39325440. Its totient is φ = 18892800.

The previous prime is 28913627. The next prime is 28913639. The reversal of 28913631 is 13631982.

It is not a de Polignac number, because 28913631 - 2² = 28913627 is a prime.

It is a super-2 number, since 2×28913631² = 1671996115208322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28913592 and 28913601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28913639) 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, 37215 + ... + 37983.

It is an arithmetic number, because the mean of its divisors is an integer number (2457840).

Almost surely, 2^28913631 is an apocalyptic number.

28913631 is a deficient number, since it is larger than the sum of its proper divisors (10411809).

28913631 is a wasteful number, since it uses less digits than its factorization.

28913631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006.

The product of its digits is 7776, while the sum is 33.

The square root of 28913631 is about 5377.1396671465. The cubic root of 28913631 is about 306.9263759054.

The spelling of 28913631 in words is "twenty-eight million, nine hundred thirteen thousand, six hundred thirty-one".