15985969818 has 256 divisors, whose sum is σ = 42539212800. Its totient is φ = 3971455488.

The previous prime is 15985969781. The next prime is 15985969837. The reversal of 15985969818 is 81896958951.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 51073230 + ... + 51073542.

It is an arithmetic number, because the mean of its divisors is an integer number (166168800).

Almost surely, 2^15985969818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15985969818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21269606400).

15985969818 is an abundant number, since it is smaller than the sum of its proper divisors (26553242982).

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

15985969818 is a wasteful number, since it uses less digits than its factorization.

15985969818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458 (or 444 counting only the distinct ones).

The product of its digits is 55987200, while the sum is 69.

The spelling of 15985969818 in words is "fifteen billion, nine hundred eighty-five million, nine hundred sixty-nine thousand, eight hundred eighteen".