81167619788 has 12 divisors (see below), whose sum is σ = 142046689680. Its totient is φ = 40582851312.

The previous prime is 81167619733. The next prime is 81167619811. The reversal of 81167619788 is 88791676118.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81167619788.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28448 + ... + 403911.

It is an arithmetic number, because the mean of its divisors is an integer number (11837224140).

Almost surely, 2^81167619788 is an apocalyptic number.

It is an amenable number.

81167619788 is a deficient number, since it is larger than the sum of its proper divisors (60879069892).

81167619788 is a wasteful number, since it uses less digits than its factorization.

81167619788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479296 (or 479294 counting only the distinct ones).

The product of its digits is 8128512, while the sum is 62.

The spelling of 81167619788 in words is "eighty-one billion, one hundred sixty-seven million, six hundred nineteen thousand, seven hundred eighty-eight".