20311801918091 has 2 divisors, whose sum is σ = 20311801918092. Its totient is φ = 20311801918090.

The previous prime is 20311801917997. The next prime is 20311801918099. The reversal of 20311801918091 is 19081910811302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20311801918091 - 2¹⁰ = 20311801917067 is a prime.

It is not a weakly prime, because it can be changed into another prime (20311801918099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10155900959045 + 10155900959046.

It is an arithmetic number, because the mean of its divisors is an integer number (10155900959046).

Almost surely, 2^{20311801918091} is an apocalyptic number.

20311801918091 is a deficient number, since it is larger than the sum of its proper divisors (1).

20311801918091 is an equidigital number, since it uses as much as digits as its factorization.

20311801918091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 44.

The spelling of 20311801918091 in words is "twenty trillion, three hundred eleven billion, eight hundred one million, nine hundred eighteen thousand, ninety-one".