28990720 has 144 divisors (see below), whose sum is σ = 79470720. Its totient is φ = 10035200.

The previous prime is 28990711. The next prime is 28990727. The reversal of 28990720 is 2709982.

It is a super-2 number, since 2×28990720² = 1680923692236800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28990720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28990727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 408285 + ... + 408355.

It is an arithmetic number, because the mean of its divisors is an integer number (551880).

Almost surely, 2^28990720 is an apocalyptic number.

28990720 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 28990720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39735360).

28990720 is an abundant number, since it is smaller than the sum of its proper divisors (50480000).

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

28990720 is a wasteful number, since it uses less digits than its factorization.

28990720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 37.

The square root of 28990720 is about 5384.3031118242. The cubic root of 28990720 is about 307.1989076929.

The spelling of 28990720 in words is "twenty-eight million, nine hundred ninety thousand, seven hundred twenty".