28515660 has 48 divisors (see below), whose sum is σ = 82424832. Its totient is φ = 7358400.

The previous prime is 28515649. The next prime is 28515667. The reversal of 28515660 is 6651582.

28515660 = 1776² + 1777² + ... + 1784².

It is not an unprimeable number, because it can be changed into a prime (28515667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5806 + ... + 9525.

It is an arithmetic number, because the mean of its divisors is an integer number (1717184).

Almost surely, 2^28515660 is an apocalyptic number.

28515660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28515660 is an abundant number, since it is smaller than the sum of its proper divisors (53909172).

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

28515660 is a wasteful number, since it uses less digits than its factorization.

28515660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15374 (or 15372 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The square root of 28515660 is about 5340.0056179746. The cubic root of 28515660 is about 305.5116736003.

The spelling of 28515660 in words is "twenty-eight million, five hundred fifteen thousand, six hundred sixty".