15939820 has 48 divisors (see below), whose sum is σ = 36465408. Its totient is φ = 5817600.

The previous prime is 15939809. The next prime is 15939827. The reversal of 15939820 is 2893951.

It is a self number, because there is not a number n which added to its sum of digits gives 15939820.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15939827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25957 + ... + 26563.

It is an arithmetic number, because the mean of its divisors is an integer number (759696).

Almost surely, 2^15939820 is an apocalyptic number.

15939820 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 15939820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18232704).

15939820 is an abundant number, since it is smaller than the sum of its proper divisors (20525588).

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

15939820 is a wasteful number, since it uses less digits than its factorization.

15939820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 730 (or 728 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 15939820 is about 3992.4704131653. The cubic root of 15939820 is about 251.6678878547.

The spelling of 15939820 in words is "fifteen million, nine hundred thirty-nine thousand, eight hundred twenty".