81935514989568 has 132 divisors (see below), whose sum is σ = 237787976034180. Its totient is φ = 27173198954496.

The previous prime is 81935514989557. The next prime is 81935514989579. The reversal of 81935514989568 is 86598941553918.

81935514989568 is a `hidden beast` number, since 8 + 1 + 9 + 3 + 5 + 5 + 1 + 49 + 8 + 9 + 568 = 666.

It is an interprime number because it is at equal distance from previous prime (81935514989557) and next prime (81935514989579).

It can be written as a sum of positive squares in 2 ways, for example, as 73497837855744 + 8437677133824 = 8573088^2 + 2904768^2 .

It is a Smith number, since the sum of its digits (81) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20749353 + ... + 24380456.

It is an arithmetic number, because the mean of its divisors is an integer number (1801424060865).

Almost surely, 2^{81935514989568} is an apocalyptic number.

It is an amenable number.

81935514989568 is an abundant number, since it is smaller than the sum of its proper divisors (155852461044612).

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

81935514989568 is a wasteful number, since it uses less digits than its factorization.

81935514989568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45130032 (or 45130011 counting only the distinct ones).

The product of its digits is 3359232000, while the sum is 81.

The spelling of 81935514989568 in words is "eighty-one trillion, nine hundred thirty-five billion, five hundred fourteen million, nine hundred eighty-nine thousand, five hundred sixty-eight".