28504231 has 12 divisors (see below), whose sum is σ = 33866208. Its totient is φ = 23910432.

The previous prime is 28504219. The next prime is 28504243. The reversal of 28504231 is 13240582.

It is an interprime number because it is at equal distance from previous prime (28504219) and next prime (28504243).

It is not a de Polignac number, because 28504231 - 2²¹ = 26407079 is a prime.

It is a super-2 number, since 2×28504231² = 1624982369802722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28504196 and 28504205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28504271) 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, 3886 + ... + 8491.

It is an arithmetic number, because the mean of its divisors is an integer number (2822184).

Almost surely, 2^28504231 is an apocalyptic number.

28504231 is a deficient number, since it is larger than the sum of its proper divisors (5361977).

28504231 is a wasteful number, since it uses less digits than its factorization.

28504231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12438 (or 12431 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 28504231 is about 5338.9353807665. The cubic root of 28504231 is about 305.4708520598.

The spelling of 28504231 in words is "twenty-eight million, five hundred four thousand, two hundred thirty-one".