28890531 has 12 divisors (see below), whose sum is σ = 44185752. Its totient is φ = 18127296.

The previous prime is 28890503. The next prime is 28890541. The reversal of 28890531 is 13509882.

It is not a de Polignac number, because 28890531 - 2⁷ = 28890403 is a prime.

It is a super-2 number, since 2×28890531² = 1669325562923922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28890541) 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, 94261 + ... + 94566.

It is an arithmetic number, because the mean of its divisors is an integer number (3682146).

Almost surely, 2^28890531 is an apocalyptic number.

28890531 is a deficient number, since it is larger than the sum of its proper divisors (15295221).

28890531 is a wasteful number, since it uses less digits than its factorization.

28890531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188850 (or 188847 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 28890531 is about 5374.9912558068. The cubic root of 28890531 is about 306.8446164489.

The spelling of 28890531 in words is "twenty-eight million, eight hundred ninety thousand, five hundred thirty-one".