28520631 has 6 divisors (see below), whose sum is σ = 41196480. Its totient is φ = 19013748.

The previous prime is 28520623. The next prime is 28520633. The reversal of 28520631 is 13602582.

28520631 is a `hidden beast` number, since 2 + 8 + 5 + 20 + 631 = 666.

It is not a de Polignac number, because 28520631 - 2³ = 28520623 is a prime.

It is a super-2 number, since 2×28520631² = 1626852785276322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28520595 and 28520604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28520633) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1584471 + ... + 1584488.

It is an arithmetic number, because the mean of its divisors is an integer number (6866080).

Almost surely, 2^28520631 is an apocalyptic number.

28520631 is a deficient number, since it is larger than the sum of its proper divisors (12675849).

28520631 is a wasteful number, since it uses less digits than its factorization.

28520631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3168965 (or 3168962 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 28520631 is about 5340.4710466400. The cubic root of 28520631 is about 305.5294253700.

The spelling of 28520631 in words is "twenty-eight million, five hundred twenty thousand, six hundred thirty-one".