81764868 has 12 divisors (see below), whose sum is σ = 190784720. Its totient is φ = 27254952.

The previous prime is 81764791. The next prime is 81764869. The reversal of 81764868 is 86846718.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (81764869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3406858 + ... + 3406881.

Almost surely, 2^81764868 is an apocalyptic number.

It is an amenable number.

81764868 is an abundant number, since it is smaller than the sum of its proper divisors (109019852).

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

81764868 is a wasteful number, since it uses less digits than its factorization.

81764868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6813746 (or 6813744 counting only the distinct ones).

The product of its digits is 516096, while the sum is 48.

The square root of 81764868 is about 9042.3928249109. The cubic root of 81764868 is about 434.0324963103.

The spelling of 81764868 in words is "eighty-one million, seven hundred sixty-four thousand, eight hundred sixty-eight".