28339920 has 120 divisors (see below), whose sum is σ = 108790656. Its totient is φ = 6476544.

The previous prime is 28339879. The next prime is 28339937. The reversal of 28339920 is 2993382.

It is a tau number, because it is divible by the number of its divisors (120).

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 23 ways as a sum of consecutive naturals, for example, 2229 + ... + 7851.

Almost surely, 2^28339920 is an apocalyptic number.

28339920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28339920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54395328).

28339920 is an abundant number, since it is smaller than the sum of its proper divisors (80450736).

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

28339920 is a wasteful number, since it uses less digits than its factorization.

28339920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5649 (or 5640 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 28339920 is about 5323.5251478696. The cubic root of 28339920 is about 304.8827642234.

The spelling of 28339920 in words is "twenty-eight million, three hundred thirty-nine thousand, nine hundred twenty".