28720808 has 8 divisors (see below), whose sum is σ = 53851530. Its totient is φ = 14360400.

The previous prime is 28720801. The next prime is 28720819. The reversal of 28720808 is 80802782.

It can be written as a sum of positive squares in only one way, i.e., 27227524 + 1493284 = 5218^2 + 1222^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (28720801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1795043 + ... + 1795058.

Almost surely, 2^28720808 is an apocalyptic number.

It is an amenable number.

28720808 is a deficient number, since it is larger than the sum of its proper divisors (25130722).

28720808 is a wasteful number, since it uses less digits than its factorization.

28720808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3590107 (or 3590103 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 28720808 is about 5359.1797879899. The cubic root of 28720808 is about 306.2425633069.

The spelling of 28720808 in words is "twenty-eight million, seven hundred twenty thousand, eight hundred eight".