15918944664 has 128 divisors (see below), whose sum is σ = 47251353600. Its totient is φ = 4373291520.

The previous prime is 15918944611. The next prime is 15918944669. The reversal of 15918944664 is 46644981951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15918944669) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 807922 + ... + 827390.

It is an arithmetic number, because the mean of its divisors is an integer number (369151200).

Almost surely, 2^15918944664 is an apocalyptic number.

15918944664 is a gapful number since it is divisible by the number (14) 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 15918944664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23625676800).

15918944664 is an abundant number, since it is smaller than the sum of its proper divisors (31332408936).

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

15918944664 is a wasteful number, since it uses less digits than its factorization.

15918944664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19673 (or 19669 counting only the distinct ones).

The product of its digits is 7464960, while the sum is 57.

The spelling of 15918944664 in words is "fifteen billion, nine hundred eighteen million, nine hundred forty-four thousand, six hundred sixty-four".