28516431 has 4 divisors (see below), whose sum is σ = 38021912. Its totient is φ = 19010952.

The previous prime is 28516409. The next prime is 28516457. The reversal of 28516431 is 13461582.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28516431 - 2⁷ = 28516303 is a prime.

It is a super-2 number, since 2×28516431² = 1626373673955522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28516031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4752736 + ... + 4752741.

It is an arithmetic number, because the mean of its divisors is an integer number (9505478).

Almost surely, 2^28516431 is an apocalyptic number.

28516431 is a deficient number, since it is larger than the sum of its proper divisors (9505481).

28516431 is an equidigital number, since it uses as much as digits as its factorization.

28516431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9505480.

The product of its digits is 5760, while the sum is 30.

The square root of 28516431 is about 5340.0778084219. The cubic root of 28516431 is about 305.5144270275.

The spelling of 28516431 in words is "twenty-eight million, five hundred sixteen thousand, four hundred thirty-one".