15999612120 has 288 divisors, whose sum is σ = 54372708000. Its totient is φ = 4079738880.

The previous prime is 15999612077. The next prime is 15999612193. The reversal of 15999612120 is 2121699951.

15999612120 is a `hidden beast` number, since 1 + 5 + 9 + 9 + 9 + 612 + 1 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 35633656 + ... + 35634104.

It is an arithmetic number, because the mean of its divisors is an integer number (188794125).

Almost surely, 2^15999612120 is an apocalyptic number.

15999612120 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 15999612120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27186354000).

15999612120 is an abundant number, since it is smaller than the sum of its proper divisors (38373095880).

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

15999612120 is a wasteful number, since it uses less digits than its factorization.

15999612120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631 (or 593 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 45.

The spelling of 15999612120 in words is "fifteen billion, nine hundred ninety-nine million, six hundred twelve thousand, one hundred twenty".