15981381988 has 48 divisors (see below), whose sum is σ = 33555965184. Its totient is φ = 6562794240.

The previous prime is 15981381971. The next prime is 15981382003. The reversal of 15981381988 is 88918318951.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 270345 + ... + 324112.

It is an arithmetic number, because the mean of its divisors is an integer number (699082608).

Almost surely, 2^15981381988 is an apocalyptic number.

It is an amenable number.

15981381988 is an abundant number, since it is smaller than the sum of its proper divisors (17574583196).

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

15981381988 is a wasteful number, since it uses less digits than its factorization.

15981381988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594532 (or 594530 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 61.

The spelling of 15981381988 in words is "fifteen billion, nine hundred eighty-one million, three hundred eighty-one thousand, nine hundred eighty-eight".