28920424 has 64 divisors (see below), whose sum is σ = 62092800. Its totient is φ = 12531456.

The previous prime is 28920403. The next prime is 28920431. The reversal of 28920424 is 42402982.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129577 + ... + 129799.

It is an arithmetic number, because the mean of its divisors is an integer number (970200).

Almost surely, 2^28920424 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28920424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31046400).

28920424 is an abundant number, since it is smaller than the sum of its proper divisors (33172376).

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

28920424 is a wasteful number, since it uses less digits than its factorization.

28920424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 28920424 is about 5377.7712855792. The cubic root of 28920424 is about 306.9504105624.

The spelling of 28920424 in words is "twenty-eight million, nine hundred twenty thousand, four hundred twenty-four".