28920864 has 48 divisors (see below), whose sum is σ = 86764608. Its totient is φ = 8262912.

The previous prime is 28920863. The next prime is 28920877. The reversal of 28920864 is 46802982.

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (28920863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20847 + ... + 22190.

It is an arithmetic number, because the mean of its divisors is an integer number (1807596).

Almost surely, 2^28920864 is an apocalyptic number.

28920864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

28920864 is an abundant number, since it is smaller than the sum of its proper divisors (57843744).

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

28920864 is a wasteful number, since it uses less digits than its factorization.

28920864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43057 (or 43049 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 28920864 is about 5377.8121945639. The cubic root of 28920864 is about 306.9519672188.

The spelling of 28920864 in words is "twenty-eight million, nine hundred twenty thousand, eight hundred sixty-four".