81371494843 has 2 divisors, whose sum is σ = 81371494844. Its totient is φ = 81371494842.

The previous prime is 81371494837. The next prime is 81371494871. The reversal of 81371494843 is 34849417318.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81371494843 - 2⁵ = 81371494811 is a prime.

It is not a weakly prime, because it can be changed into another prime (81371494873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40685747421 + 40685747422.

It is an arithmetic number, because the mean of its divisors is an integer number (40685747422).

Almost surely, 2^81371494843 is an apocalyptic number.

81371494843 is a deficient number, since it is larger than the sum of its proper divisors (1).

81371494843 is an equidigital number, since it uses as much as digits as its factorization.

81371494843 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2322432, while the sum is 52.

The spelling of 81371494843 in words is "eighty-one billion, three hundred seventy-one million, four hundred ninety-four thousand, eight hundred forty-three".