81995568 has 40 divisors (see below), whose sum is σ = 212153088. Its totient is φ = 27289152.

The previous prime is 81995533. The next prime is 81995569. The reversal of 81995568 is 86559918.

It is a self number, because there is not a number n which added to its sum of digits gives 81995568.

It is not an unprimeable number, because it can be changed into a prime (81995569) 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, 50221 + ... + 51827.

Almost surely, 2^81995568 is an apocalyptic number.

It is an amenable number.

81995568 is an abundant number, since it is smaller than the sum of its proper divisors (130157520).

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

81995568 is a wasteful number, since it uses less digits than its factorization.

81995568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2681 (or 2675 counting only the distinct ones).

The product of its digits is 777600, while the sum is 51.

The square root of 81995568 is about 9055.1404185689. The cubic root of 81995568 is about 434.4403213050.

The spelling of 81995568 in words is "eighty-one million, nine hundred ninety-five thousand, five hundred sixty-eight".