81955891336356 has 48 divisors (see below), whose sum is σ = 213590688353280. Its totient is φ = 27175600959840.

The previous prime is 81955891336343. The next prime is 81955891336393. The reversal of 81955891336356 is 65363319855918.

81955891336356 is a `hidden beast` number, since 8 + 1 + 9 + 5 + 589 + 1 + 3 + 3 + 6 + 35 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1986499911 + ... + 1986541166.

It is an arithmetic number, because the mean of its divisors is an integer number (4449806007360).

Almost surely, 2^{81955891336356} is an apocalyptic number.

It is an amenable number.

81955891336356 is an abundant number, since it is smaller than the sum of its proper divisors (131634797016924).

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

81955891336356 is a wasteful number, since it uses less digits than its factorization.

81955891336356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3973041281 (or 3973041273 counting only the distinct ones).

The product of its digits is 629856000, while the sum is 72.

The spelling of 81955891336356 in words is "eighty-one trillion, nine hundred fifty-five billion, eight hundred ninety-one million, three hundred thirty-six thousand, three hundred fifty-six".