28817631 has 12 divisors (see below), whose sum is σ = 42968640. Its totient is φ = 18591840.

The previous prime is 28817603. The next prime is 28817639. The reversal of 28817631 is 13671882.

28817631 is a `hidden beast` number, since 2 + 8 + 8 + 17 + 631 = 666.

It is not a de Polignac number, because 28817631 - 2¹³ = 28809439 is a prime.

It is a super-2 number, since 2×28817631² = 1660911712904322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28817639) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51366 + ... + 51923.

It is an arithmetic number, because the mean of its divisors is an integer number (3580720).

Almost surely, 2^28817631 is an apocalyptic number.

28817631 is a deficient number, since it is larger than the sum of its proper divisors (14151009).

28817631 is a wasteful number, since it uses less digits than its factorization.

28817631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103326 (or 103323 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 28817631 is about 5368.2055661087. The cubic root of 28817631 is about 306.5863102051.

The spelling of 28817631 in words is "twenty-eight million, eight hundred seventeen thousand, six hundred thirty-one".