28725616 has 20 divisors (see below), whose sum is σ = 57161272. Its totient is φ = 13974336.

The previous prime is 28725611. The next prime is 28725691. The reversal of 28725616 is 61652782.

It is a happy number.

It is a super-2 number, since 2×28725616² = 1650322029158912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28725611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23670 + ... + 24853.

Almost surely, 2^28725616 is an apocalyptic number.

It is an amenable number.

28725616 is a deficient number, since it is larger than the sum of its proper divisors (28435656).

28725616 is a wasteful number, since it uses less digits than its factorization.

28725616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48568 (or 48562 counting only the distinct ones).

The product of its digits is 40320, while the sum is 37.

The square root of 28725616 is about 5359.6283453240. The cubic root of 28725616 is about 306.2596511744.

The spelling of 28725616 in words is "twenty-eight million, seven hundred twenty-five thousand, six hundred sixteen".