15999344640 has 896 divisors, whose sum is σ = 64546398720. Its totient is φ = 3737124864.

The previous prime is 15999344639. The next prime is 15999344651. The reversal of 15999344640 is 4644399951.

It is a happy number.

15999344640 is a `hidden beast` number, since 1 + 5 + 99 + 93 + 4 + 464 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 432414702 + ... + 432414738.

Almost surely, 2^15999344640 is an apocalyptic number.

15999344640 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 15999344640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32273199360).

15999344640 is an abundant number, since it is smaller than the sum of its proper divisors (48547054080).

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

15999344640 is a wasteful number, since it uses less digits than its factorization.

15999344640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117 (or 87 counting only the distinct ones).

The product of its (nonzero) digits is 4199040, while the sum is 54.

The spelling of 15999344640 in words is "fifteen billion, nine hundred ninety-nine million, three hundred forty-four thousand, six hundred forty".