28667931 has 8 divisors (see below), whose sum is σ = 38251584. Its totient is φ = 19098120.

The previous prime is 28667929. The next prime is 28667953. The reversal of 28667931 is 13976682.

It is a happy number.

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

It is not a de Polignac number, because 28667931 - 2¹ = 28667929 is a prime.

It is a super-2 number, since 2×28667931² = 1643700535641522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28667911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3216 + ... + 8226.

It is an arithmetic number, because the mean of its divisors is an integer number (4781448).

Almost surely, 2^28667931 is an apocalyptic number.

28667931 is a deficient number, since it is larger than the sum of its proper divisors (9583653).

28667931 is a wasteful number, since it uses less digits than its factorization.

28667931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6921.

The product of its digits is 108864, while the sum is 42.

The square root of 28667931 is about 5354.2442043672. The cubic root of 28667931 is about 306.0545099184.

The spelling of 28667931 in words is "twenty-eight million, six hundred sixty-seven thousand, nine hundred thirty-one".