211131955891 has 2 divisors, whose sum is σ = 211131955892. Its totient is φ = 211131955890.

The previous prime is 211131955871. The next prime is 211131955897. The reversal of 211131955891 is 198559131112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 211131955891 - 2²⁷ = 210997738163 is a prime.

It is not a weakly prime, because it can be changed into another prime (211131955897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105565977945 + 105565977946.

It is an arithmetic number, because the mean of its divisors is an integer number (105565977946).

Almost surely, 2^211131955891 is an apocalyptic number.

211131955891 is a deficient number, since it is larger than the sum of its proper divisors (1).

211131955891 is an equidigital number, since it uses as much as digits as its factorization.

211131955891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 46.

The spelling of 211131955891 in words is "two hundred eleven billion, one hundred thirty-one million, nine hundred fifty-five thousand, eight hundred ninety-one".