81117473660 has 24 divisors (see below), whose sum is σ = 170392145616. Its totient is φ = 32438332160.

The previous prime is 81117473651. The next prime is 81117473681. The reversal of 81117473660 is 6637471118.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 463982 + ... + 614421.

It is an arithmetic number, because the mean of its divisors is an integer number (7099672734).

Almost surely, 2^81117473660 is an apocalyptic number.

It is an amenable number.

81117473660 is an abundant number, since it is smaller than the sum of its proper divisors (89274671956).

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

81117473660 is a wasteful number, since it uses less digits than its factorization.

81117473660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082173 (or 1082171 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 44.

The spelling of 81117473660 in words is "eighty-one billion, one hundred seventeen million, four hundred seventy-three thousand, six hundred sixty".