28257660 has 60 divisors (see below), whose sum is σ = 88650408. Its totient is φ = 7534944.

The previous prime is 28257659. The next prime is 28257707. The reversal of 28257660 is 6675282.

28257660 is a `hidden beast` number, since 2 + 82 + 576 + 6 + 0 = 666.

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

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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, 7102 + ... + 10341.

Almost surely, 2^28257660 is an apocalyptic number.

28257660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28257660 is an abundant number, since it is smaller than the sum of its proper divisors (60392748).

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

28257660 is a wasteful number, since it uses less digits than its factorization.

28257660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17464 (or 17453 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 28257660 is about 5315.7934497119. The cubic root of 28257660 is about 304.5874921483.

The spelling of 28257660 in words is "twenty-eight million, two hundred fifty-seven thousand, six hundred sixty".