15720 has 32 divisors (see below), whose sum is σ = 47520. Its totient is φ = 4160.

The previous prime is 15683. The next prime is 15727. The reversal of 15720 is 2751.

15720 = T₅₁ + T₅₂ + ... + T₆₀.

It is a happy number.

It is a hoax number, since the sum of its digits (15) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 15720.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 15720.

It is not an unprimeable number, because it can be changed into a prime (15727) 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, 55 + ... + 185.

It is an arithmetic number, because the mean of its divisors is an integer number (1485).

2¹⁵⁷²⁰ is an apocalyptic number.

15720 is a gapful number since it is divisible by the number (10) 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 15720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23760).

15720 is an abundant number, since it is smaller than the sum of its proper divisors (31800).

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

15720 is a wasteful number, since it uses less digits than its factorization.

15720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 70, while the sum is 15.

The square root of 15720 is about 125.3794241493. The cubic root of 15720 is about 25.0505643277.

The spelling of 15720 in words is "fifteen thousand, seven hundred twenty".