28431290 has 16 divisors (see below), whose sum is σ = 51238440. Its totient is φ = 11358720.

The previous prime is 28431269. The next prime is 28431313. The reversal of 28431290 is 9213482.

It can be written as a sum of positive squares in 4 ways, for example, as 23551609 + 4879681 = 4853^2 + 2209^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12566 + ... + 14654.

Almost surely, 2^28431290 is an apocalyptic number.

28431290 is a deficient number, since it is larger than the sum of its proper divisors (22807150).

28431290 is a wasteful number, since it uses less digits than its factorization.

28431290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3457.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 28431290 is about 5332.0999615536. The cubic root of 28431290 is about 305.2100675920.

The spelling of 28431290 in words is "twenty-eight million, four hundred thirty-one thousand, two hundred ninety".