15728720 has 40 divisors (see below), whose sum is σ = 41794944. Its totient is φ = 5392512.

The previous prime is 15728717. The next prime is 15728729. The reversal of 15728720 is 2782751.

It is a tau number, because it is divible by the number of its divisors (40).

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15728729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13484 + ... + 14603.

Almost surely, 2^15728720 is an apocalyptic number.

15728720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15728720 is an abundant number, since it is smaller than the sum of its proper divisors (26066224).

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

15728720 is a wasteful number, since it uses less digits than its factorization.

15728720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28107 (or 28101 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 15728720 is about 3965.9450323977. The cubic root of 15728720 is about 250.5519538244.

The spelling of 15728720 in words is "fifteen million, seven hundred twenty-eight thousand, seven hundred twenty".