91819109237 has 2 divisors, whose sum is σ = 91819109238. Its totient is φ = 91819109236.

The previous prime is 91819109177. The next prime is 91819109299. The reversal of 91819109237 is 73290191819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65637927601 + 26181181636 = 256199^2 + 161806^2 .

It is a cyclic number.

It is not a de Polignac number, because 91819109237 - 2⁸ = 91819108981 is a prime.

It is a super-2 number, since 2×91819109237² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91819103237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45909554618 + 45909554619.

It is an arithmetic number, because the mean of its divisors is an integer number (45909554619).

Almost surely, 2^91819109237 is an apocalyptic number.

It is an amenable number.

91819109237 is a deficient number, since it is larger than the sum of its proper divisors (1).

91819109237 is an equidigital number, since it uses as much as digits as its factorization.

91819109237 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 50.

The spelling of 91819109237 in words is "ninety-one billion, eight hundred nineteen million, one hundred nine thousand, two hundred thirty-seven".