15981344568 has 192 divisors, whose sum is σ = 50734844160. Its totient is φ = 4449489408.

The previous prime is 15981344549. The next prime is 15981344629. The reversal of 15981344568 is 86544318951.

It is a happy number.

15981344568 is a `hidden beast` number, since 1 + 59 + 8 + 134 + 456 + 8 = 666.

It is a super-2 number, since 2×15981344568² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17055396 + ... + 17056332.

It is an arithmetic number, because the mean of its divisors is an integer number (264243980).

Almost surely, 2^15981344568 is an apocalyptic number.

15981344568 is a gapful number since it is divisible by the number (18) 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 15981344568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25367422080).

15981344568 is an abundant number, since it is smaller than the sum of its proper divisors (34753499592).

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

15981344568 is a wasteful number, since it uses less digits than its factorization.

15981344568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1786 (or 1779 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 54.

The spelling of 15981344568 in words is "fifteen billion, nine hundred eighty-one million, three hundred forty-four thousand, five hundred sixty-eight".