81738585499 has 2 divisors, whose sum is σ = 81738585500. Its totient is φ = 81738585498.

The previous prime is 81738585473. The next prime is 81738585521. The reversal of 81738585499 is 99458583718.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81738585499 - 2¹⁹ = 81738061211 is a prime.

It is not a weakly prime, because it can be changed into another prime (81738585449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40869292749 + 40869292750.

It is an arithmetic number, because the mean of its divisors is an integer number (40869292750).

Almost surely, 2^81738585499 is an apocalyptic number.

81738585499 is a deficient number, since it is larger than the sum of its proper divisors (1).

81738585499 is an equidigital number, since it uses as much as digits as its factorization.

81738585499 is an evil number, because the sum of its binary digits is even.

The product of its digits is 87091200, while the sum is 67.

The spelling of 81738585499 in words is "eighty-one billion, seven hundred thirty-eight million, five hundred eighty-five thousand, four hundred ninety-nine".