28931568 has 80 divisors (see below), whose sum is σ = 78140832. Its totient is φ = 9216000.

The previous prime is 28931557. The next prime is 28931593. The reversal of 28931568 is 86513982.

It is a congruent number.

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, 119928 + ... + 120168.

Almost surely, 2^28931568 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 28931568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39070416).

28931568 is an abundant number, since it is smaller than the sum of its proper divisors (49209264).

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

28931568 is a wasteful number, since it uses less digits than its factorization.

28931568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354 (or 348 counting only the distinct ones).

The product of its digits is 103680, while the sum is 42.

The square root of 28931568 is about 5378.8073027391. The cubic root of 28931568 is about 306.9898315624.

The spelling of 28931568 in words is "twenty-eight million, nine hundred thirty-one thousand, five hundred sixty-eight".