28667631 has 16 divisors (see below), whose sum is σ = 39684960. Its totient is φ = 18385920.

The previous prime is 28667629. The next prime is 28667663. The reversal of 28667631 is 13676682.

It is not a de Polignac number, because 28667631 - 2¹ = 28667629 is a prime.

It is a super-2 number, since 2×28667631² = 1643666134304322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28667631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28667231) 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, 37291 + ... + 38051.

It is an arithmetic number, because the mean of its divisors is an integer number (2480310).

Almost surely, 2^28667631 is an apocalyptic number.

28667631 is a deficient number, since it is larger than the sum of its proper divisors (11017329).

28667631 is a wasteful number, since it uses less digits than its factorization.

28667631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1226.

The product of its digits is 72576, while the sum is 39.

The square root of 28667631 is about 5354.2161891354. The cubic root of 28667631 is about 306.0534423297.

The spelling of 28667631 in words is "twenty-eight million, six hundred sixty-seven thousand, six hundred thirty-one".