81178634416 has 40 divisors (see below), whose sum is σ = 172634825664. Its totient is φ = 36672989760.

The previous prime is 81178634401. The next prime is 81178634423. The reversal of 81178634416 is 61443687118.

It is a happy number.

It is a super-2 number, since 2×81178634416² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 81178634416.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1386166 + ... + 1443541.

Almost surely, 2^81178634416 is an apocalyptic number.

It is an amenable number.

81178634416 is an abundant number, since it is smaller than the sum of its proper divisors (91456191248).

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

81178634416 is a wasteful number, since it uses less digits than its factorization.

81178634416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2829889 (or 2829883 counting only the distinct ones).

The product of its digits is 774144, while the sum is 49.

The spelling of 81178634416 in words is "eighty-one billion, one hundred seventy-eight million, six hundred thirty-four thousand, four hundred sixteen".