28663620 has 24 divisors (see below), whose sum is σ = 80258304. Its totient is φ = 7643616.

The previous prime is 28663603. The next prime is 28663631. The reversal of 28663620 is 2636682.

It is a super-2 number, since 2×28663620² = 1643206223008800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 238804 + ... + 238923.

It is an arithmetic number, because the mean of its divisors is an integer number (3344096).

Almost surely, 2^28663620 is an apocalyptic number.

28663620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28663620 is an abundant number, since it is smaller than the sum of its proper divisors (51594684).

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

28663620 is a wasteful number, since it uses less digits than its factorization.

28663620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477739 (or 477737 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 28663620 is about 5353.8416114039. The cubic root of 28663620 is about 306.0391679540.

The spelling of 28663620 in words is "twenty-eight million, six hundred sixty-three thousand, six hundred twenty".