81641289599 has 2 divisors, whose sum is σ = 81641289600. Its totient is φ = 81641289598.

The previous prime is 81641289571. The next prime is 81641289619. The reversal of 81641289599 is 99598214618.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81641289599 - 2³² = 77346322303 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81641289529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40820644799 + 40820644800.

It is an arithmetic number, because the mean of its divisors is an integer number (40820644800).

Almost surely, 2^81641289599 is an apocalyptic number.

81641289599 is a deficient number, since it is larger than the sum of its proper divisors (1).

81641289599 is an equidigital number, since it uses as much as digits as its factorization.

81641289599 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11197440, while the sum is 62.

The spelling of 81641289599 in words is "eighty-one billion, six hundred forty-one million, two hundred eighty-nine thousand, five hundred ninety-nine".