28431320 has 32 divisors (see below), whose sum is σ = 65182320. Its totient is φ = 11157120.

The previous prime is 28431313. The next prime is 28431331. The reversal of 28431320 is 2313482.

It is a congruent 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, 4586 + ... + 8825.

Almost surely, 2^28431320 is an apocalyptic number.

28431320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28431320 is an abundant number, since it is smaller than the sum of its proper divisors (36751000).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28431320 is a wasteful number, since it uses less digits than its factorization.

28431320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13475 (or 13471 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 28431320 is about 5332.1027747034. The cubic root of 28431320 is about 305.2101749421.

The spelling of 28431320 in words is "twenty-eight million, four hundred thirty-one thousand, three hundred twenty".