81967378416 has 80 divisors (see below), whose sum is σ = 263998841088. Its totient is φ = 21290227200.

The previous prime is 81967378399. The next prime is 81967378457. The reversal of 81967378416 is 61487376918.

It is a super-2 number, since 2×81967378416² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81967378416.

It is a congruent number.

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, 11084965 + ... + 11092356.

Almost surely, 2^81967378416 is an apocalyptic number.

It is an amenable number.

81967378416 is an abundant number, since it is smaller than the sum of its proper divisors (182031462672).

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

81967378416 is a wasteful number, since it uses less digits than its factorization.

81967378416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22177350 (or 22177344 counting only the distinct ones).

The product of its digits is 12192768, while the sum is 60.

The spelling of 81967378416 in words is "eighty-one billion, nine hundred sixty-seven million, three hundred seventy-eight thousand, four hundred sixteen".