81935400971 has 2 divisors, whose sum is σ = 81935400972. Its totient is φ = 81935400970.

The previous prime is 81935400889. The next prime is 81935400983. The reversal of 81935400971 is 17900453918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81935400971 - 2³⁰ = 80861659147 is a prime.

It is not a weakly prime, because it can be changed into another prime (81935400571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40967700485 + 40967700486.

It is an arithmetic number, because the mean of its divisors is an integer number (40967700486).

Almost surely, 2^81935400971 is an apocalyptic number.

81935400971 is a deficient number, since it is larger than the sum of its proper divisors (1).

81935400971 is an equidigital number, since it uses as much as digits as its factorization.

81935400971 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 272160, while the sum is 47.

The spelling of 81935400971 in words is "eighty-one billion, nine hundred thirty-five million, four hundred thousand, nine hundred seventy-one".