81664176 has 40 divisors (see below), whose sum is σ = 230145984. Its totient is φ = 24746560.

The previous prime is 81664171. The next prime is 81664189. The reversal of 81664176 is 67146618.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81664171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76806 + ... + 77861.

Almost surely, 2^81664176 is an apocalyptic number.

It is an amenable number.

81664176 is an abundant number, since it is smaller than the sum of its proper divisors (148481808).

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

81664176 is a wasteful number, since it uses less digits than its factorization.

81664176 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154689 (or 154683 counting only the distinct ones).

The product of its digits is 48384, while the sum is 39.

The square root of 81664176 is about 9036.8233356639. The cubic root of 81664176 is about 433.8542553226.

The spelling of 81664176 in words is "eighty-one million, six hundred sixty-four thousand, one hundred seventy-six".