71987999664 has 160 divisors (see below), whose sum is σ = 220378752000. Its totient is φ = 19812344832.

The previous prime is 71987999659. The next prime is 71987999717. The reversal of 71987999664 is 46699978917.

It is a super-2 number, since 2×71987999664² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4269202 + ... + 4286030.

It is an arithmetic number, because the mean of its divisors is an integer number (1377367200).

Almost surely, 2^71987999664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71987999664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110189376000).

71987999664 is an abundant number, since it is smaller than the sum of its proper divisors (148390752336).

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

71987999664 is a wasteful number, since it uses less digits than its factorization.

71987999664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17315 (or 17309 counting only the distinct ones).

The product of its digits is 370355328, while the sum is 75.

The spelling of 71987999664 in words is "seventy-one billion, nine hundred eighty-seven million, nine hundred ninety-nine thousand, six hundred sixty-four".