28812520 has 48 divisors (see below), whose sum is σ = 71269380. Its totient is φ = 10475520.

The previous prime is 28812517. The next prime is 28812521. The reversal of 28812520 is 2521882.

It can be written as a sum of positive squares in 2 ways, for example, as 24068836 + 4743684 = 4906^2 + 2178^2 .

It is a super-2 number, since 2×28812520² = 1660322617500800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28812521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1864 + ... + 7816.

Almost surely, 2^28812520 is an apocalyptic number.

28812520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28812520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35634690).

28812520 is an abundant number, since it is smaller than the sum of its proper divisors (42456860).

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

28812520 is a wasteful number, since it uses less digits than its factorization.

28812520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5986 (or 5971 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 28812520 is about 5367.7295013814. The cubic root of 28812520 is about 306.5681840878.

The spelling of 28812520 in words is "twenty-eight million, eight hundred twelve thousand, five hundred twenty".