15999120 has 120 divisors (see below), whose sum is σ = 55788096. Its totient is φ = 4261248.

The previous prime is 15999119. The next prime is 15999127. The reversal of 15999120 is 2199951.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (15999127) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19029 + ... + 19851.

Almost surely, 2^15999120 is an apocalyptic number.

15999120 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 15999120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27894048).

15999120 is an abundant number, since it is smaller than the sum of its proper divisors (39788976).

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

15999120 is an equidigital number, since it uses as much as digits as its factorization.

15999120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851 (or 833 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 15999120 is about 3999.8899984875. The cubic root of 15999120 is about 251.9795901838.

The spelling of 15999120 in words is "fifteen million, nine hundred ninety-nine thousand, one hundred twenty".