81648084589 has 2 divisors, whose sum is σ = 81648084590. Its totient is φ = 81648084588.

The previous prime is 81648084559. The next prime is 81648084599. The reversal of 81648084589 is 98548084618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71360039689 + 10288044900 = 267133^2 + 101430^2 .

It is a cyclic number.

It is not a de Polignac number, because 81648084589 - 2⁷ = 81648084461 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81648084559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40824042294 + 40824042295.

It is an arithmetic number, because the mean of its divisors is an integer number (40824042295).

Almost surely, 2^81648084589 is an apocalyptic number.

It is an amenable number.

81648084589 is a deficient number, since it is larger than the sum of its proper divisors (1).

81648084589 is an equidigital number, since it uses as much as digits as its factorization.

81648084589 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17694720, while the sum is 61.

The spelling of 81648084589 in words is "eighty-one billion, six hundred forty-eight million, eighty-four thousand, five hundred eighty-nine".