28481720 has 32 divisors (see below), whose sum is σ = 64346400. Its totient is φ = 11346048.

The previous prime is 28481707. The next prime is 28481737. The reversal of 28481720 is 2718482.

It is a super-2 number, since 2×28481720² = 1622416748316800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9437 + ... + 12083.

It is an arithmetic number, because the mean of its divisors is an integer number (2010825).

Almost surely, 2^28481720 is an apocalyptic number.

28481720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28481720 is an abundant number, since it is smaller than the sum of its proper divisors (35864680).

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

28481720 is a wasteful number, since it uses less digits than its factorization.

28481720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2927 (or 2923 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 28481720 is about 5336.8267725307. The cubic root of 28481720 is about 305.3904164530.

The spelling of 28481720 in words is "twenty-eight million, four hundred eighty-one thousand, seven hundred twenty".