28028664 has 24 divisors (see below), whose sum is σ = 75911160. Its totient is φ = 9342864.

The previous prime is 28028659. The next prime is 28028701. The reversal of 28028664 is 46682082.

It is a tau number, because it is divible by the number of its divisors (24).

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 5 ways as a sum of consecutive naturals, for example, 194572 + ... + 194715.

It is an arithmetic number, because the mean of its divisors is an integer number (3162965).

Almost surely, 2^28028664 is an apocalyptic number.

28028664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

28028664 is an abundant number, since it is smaller than the sum of its proper divisors (47882496).

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

28028664 is a wasteful number, since it uses less digits than its factorization.

28028664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389299 (or 389292 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 36.

The square root of 28028664 is about 5294.2104227165. The cubic root of 28028664 is about 303.7624818323.

The spelling of 28028664 in words is "twenty-eight million, twenty-eight thousand, six hundred sixty-four".