81806976 has 64 divisors (see below), whose sum is σ = 241454400. Its totient is φ = 27267840.

The previous prime is 81806969. The next prime is 81806993. The reversal of 81806976 is 67960818.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

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, 8380 + ... + 15291.

It is an arithmetic number, because the mean of its divisors is an integer number (3772725).

Almost surely, 2^81806976 is an apocalyptic number.

It is an amenable number.

81806976 is an abundant number, since it is smaller than the sum of its proper divisors (159647424).

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

81806976 is a wasteful number, since it uses less digits than its factorization.

81806976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23694 (or 23676 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 81806976 is about 9044.7208912160. The cubic root of 81806976 is about 434.1069908307.

The spelling of 81806976 in words is "eighty-one million, eight hundred six thousand, nine hundred seventy-six".