28304140 has 12 divisors (see below), whose sum is σ = 59438736. Its totient is φ = 11321648.

The previous prime is 28304131. The next prime is 28304161. The reversal of 28304140 is 4140382.

It is a super-2 number, since 2×28304140² = 1602248682279200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 707584 + ... + 707623.

It is an arithmetic number, because the mean of its divisors is an integer number (4953228).

Almost surely, 2^28304140 is an apocalyptic number.

28304140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28304140 is an abundant number, since it is smaller than the sum of its proper divisors (31134596).

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

28304140 is a wasteful number, since it uses less digits than its factorization.

28304140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1415216 (or 1415214 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 28304140 is about 5320.1635313212. The cubic root of 28304140 is about 304.7544023063.

The spelling of 28304140 in words is "twenty-eight million, three hundred four thousand, one hundred forty".