81000017995933 has 2 divisors, whose sum is σ = 81000017995934. Its totient is φ = 81000017995932.

The previous prime is 81000017995877. The next prime is 81000017995961. The reversal of 81000017995933 is 33959971000018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77492139973444 + 3507878022489 = 8802962^2 + 1872933^2 .

It is a cyclic number.

It is not a de Polignac number, because 81000017995933 - 2²⁹ = 80999481125021 is a prime.

It is a super-2 number, since 2×81000017995933² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81000017995033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40500008997966 + 40500008997967.

It is an arithmetic number, because the mean of its divisors is an integer number (40500008997967).

Almost surely, 2^{81000017995933} is an apocalyptic number.

It is an amenable number.

81000017995933 is a deficient number, since it is larger than the sum of its proper divisors (1).

81000017995933 is an equidigital number, since it uses as much as digits as its factorization.

81000017995933 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1837080, while the sum is 55.

The spelling of 81000017995933 in words is "eighty-one trillion, seventeen million, nine hundred ninety-five thousand, nine hundred thirty-three".