81167664 has 20 divisors (see below), whose sum is σ = 209683256. Its totient is φ = 27055872.

The previous prime is 81167663. The next prime is 81167683. The reversal of 81167664 is 46676118.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (81167663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 845449 + ... + 845544.

Almost surely, 2^81167664 is an apocalyptic number.

It is an amenable number.

81167664 is an abundant number, since it is smaller than the sum of its proper divisors (128515592).

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

81167664 is a wasteful number, since it uses less digits than its factorization.

81167664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691004 (or 1690998 counting only the distinct ones).

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

The square root of 81167664 is about 9009.3098514814. The cubic root of 81167664 is about 432.9732003247.

The spelling of 81167664 in words is "eighty-one million, one hundred sixty-seven thousand, six hundred sixty-four".