81935400571 has 2 divisors, whose sum is σ = 81935400572. Its totient is φ = 81935400570.

The previous prime is 81935400541. The next prime is 81935400581. The reversal of 81935400571 is 17500453918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81935400571 - 2⁵ = 81935400539 is a prime.

It is not a weakly prime, because it can be changed into another prime (81935400511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40967700285 + 40967700286.

It is an arithmetic number, because the mean of its divisors is an integer number (40967700286).

Almost surely, 2^81935400571 is an apocalyptic number.

81935400571 is a deficient number, since it is larger than the sum of its proper divisors (1).

81935400571 is an equidigital number, since it uses as much as digits as its factorization.

81935400571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 151200, while the sum is 43.

The spelling of 81935400571 in words is "eighty-one billion, nine hundred thirty-five million, four hundred thousand, five hundred seventy-one".