91819109291 has 12 divisors (see below), whose sum is σ = 113629059792. Its totient is φ = 72648085536.

The previous prime is 91819109237. The next prime is 91819109299. The reversal of 91819109291 is 19290191819.

It is not a de Polignac number, because 91819109291 - 2¹⁴ = 91819092907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91819109299) 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 in 11 ways as a sum of consecutive naturals, for example, 38806556 + ... + 38808921.

It is an arithmetic number, because the mean of its divisors is an integer number (9469088316).

Almost surely, 2^91819109291 is an apocalyptic number.

91819109291 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

91819109291 is a deficient number, since it is larger than the sum of its proper divisors (21809950501).

91819109291 is a wasteful number, since it uses less digits than its factorization.

91819109291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77615510 (or 77615497 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 50.

The spelling of 91819109291 in words is "ninety-one billion, eight hundred nineteen million, one hundred nine thousand, two hundred ninety-one".