81190637399233 has 2 divisors, whose sum is σ = 81190637399234. Its totient is φ = 81190637399232.

The previous prime is 81190637399231. The next prime is 81190637399257. The reversal of 81190637399233 is 33299373609118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68578074691344 + 12612562707889 = 8281188^2 + 3551417^2 .

It is a cyclic number.

It is not a de Polignac number, because 81190637399233 - 2¹ = 81190637399231 is a prime.

Together with 81190637399231, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (81190637399231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40595318699616 + 40595318699617.

It is an arithmetic number, because the mean of its divisors is an integer number (40595318699617).

Almost surely, 2^{81190637399233} is an apocalyptic number.

It is an amenable number.

81190637399233 is a deficient number, since it is larger than the sum of its proper divisors (1).

81190637399233 is an equidigital number, since it uses as much as digits as its factorization.

81190637399233 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39680928, while the sum is 64.

The spelling of 81190637399233 in words is "eighty-one trillion, one hundred ninety billion, six hundred thirty-seven million, three hundred ninety-nine thousand, two hundred thirty-three".