999918240091 has 2 divisors, whose sum is σ = 999918240092. Its totient is φ = 999918240090.

The previous prime is 999918240073. The next prime is 999918240173. The reversal of 999918240091 is 190042819999.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 999918240091 - 2⁷ = 999918239963 is a prime.

It is not a weakly prime, because it can be changed into another prime (999918240491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499959120045 + 499959120046.

It is an arithmetic number, because the mean of its divisors is an integer number (499959120046).

Almost surely, 2^999918240091 is an apocalyptic number.

999918240091 is a deficient number, since it is larger than the sum of its proper divisors (1).

999918240091 is an equidigital number, since it uses as much as digits as its factorization.

999918240091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3779136, while the sum is 61.

The spelling of 999918240091 in words is "nine hundred ninety-nine billion, nine hundred eighteen million, two hundred forty thousand, ninety-one".