28631631 has 48 divisors (see below), whose sum is σ = 47044608. Its totient is φ = 15422400.

The previous prime is 28631623. The next prime is 28631663. The reversal of 28631631 is 13613682.

28631631 = 946² + 947² + ... + 976².

It is not a de Polignac number, because 28631631 - 2³ = 28631623 is a prime.

It is a super-2 number, since 2×28631631² = 1639540587440322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28631731) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 277926 + ... + 278028.

It is an arithmetic number, because the mean of its divisors is an integer number (980096).

Almost surely, 2^28631631 is an apocalyptic number.

28631631 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28631631 is a deficient number, since it is larger than the sum of its proper divisors (18412977).

28631631 is a wasteful number, since it uses less digits than its factorization.

28631631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212 (or 205 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 28631631 is about 5350.8532964379. The cubic root of 28631631 is about 305.9252775813.

The spelling of 28631631 in words is "twenty-eight million, six hundred thirty-one thousand, six hundred thirty-one".