91939321849 has 2 divisors, whose sum is σ = 91939321850. Its totient is φ = 91939321848.

The previous prime is 91939321823. The next prime is 91939321871. The reversal of 91939321849 is 94812393919.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56710659600 + 35228662249 = 238140^2 + 187693^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91939321849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91939321793 and 91939321802.

It is not a weakly prime, because it can be changed into another prime (91939328849) 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, 45969660924 + 45969660925.

It is an arithmetic number, because the mean of its divisors is an integer number (45969660925).

Almost surely, 2^91939321849 is an apocalyptic number.

It is an amenable number.

91939321849 is a deficient number, since it is larger than the sum of its proper divisors (1).

91939321849 is an equidigital number, since it uses as much as digits as its factorization.

91939321849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3779136, while the sum is 58.

The spelling of 91939321849 in words is "ninety-one billion, nine hundred thirty-nine million, three hundred twenty-one thousand, eight hundred forty-nine".