81758637199 has 2 divisors, whose sum is σ = 81758637200. Its totient is φ = 81758637198.

The previous prime is 81758637151. The next prime is 81758637227. The reversal of 81758637199 is 99173685718.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81758637199 - 2¹⁷ = 81758506127 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81758637199.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81758637109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40879318599 + 40879318600.

It is an arithmetic number, because the mean of its divisors is an integer number (40879318600).

Almost surely, 2^81758637199 is an apocalyptic number.

81758637199 is a deficient number, since it is larger than the sum of its proper divisors (1).

81758637199 is an equidigital number, since it uses as much as digits as its factorization.

81758637199 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22861440, while the sum is 64.

The spelling of 81758637199 in words is "eighty-one billion, seven hundred fifty-eight million, six hundred thirty-seven thousand, one hundred ninety-nine".