28312740 has 60 divisors (see below), whose sum is σ = 88823196. Its totient is φ = 7549632.

The previous prime is 28312727. The next prime is 28312751. The reversal of 28312740 is 4721382.

It can be written as a sum of positive squares in 2 ways, for example, as 5731236 + 22581504 = 2394^2 + 4752^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×28312740² = 1603222492615200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7119 + ... + 10358.

Almost surely, 2^28312740 is an apocalyptic number.

28312740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28312740 is an abundant number, since it is smaller than the sum of its proper divisors (60510456).

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

28312740 is a wasteful number, since it uses less digits than its factorization.

28312740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17498 (or 17487 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 28312740 is about 5320.9717157677. The cubic root of 28312740 is about 304.7852649582.

The spelling of 28312740 in words is "twenty-eight million, three hundred twelve thousand, seven hundred forty".