81952220291 has 2 divisors, whose sum is σ = 81952220292. Its totient is φ = 81952220290.

The previous prime is 81952220237. The next prime is 81952220321. The reversal of 81952220291 is 19202225918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81952220291 - 2¹⁸ = 81951958147 is a prime.

It is not a weakly prime, because it can be changed into another prime (81952220491) 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, 40976110145 + 40976110146.

It is an arithmetic number, because the mean of its divisors is an integer number (40976110146).

Almost surely, 2^81952220291 is an apocalyptic number.

81952220291 is a deficient number, since it is larger than the sum of its proper divisors (1).

81952220291 is an equidigital number, since it uses as much as digits as its factorization.

81952220291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 41.

The spelling of 81952220291 in words is "eighty-one billion, nine hundred fifty-two million, two hundred twenty thousand, two hundred ninety-one".