211212220091 has 2 divisors, whose sum is σ = 211212220092. Its totient is φ = 211212220090.

The previous prime is 211212220061. The next prime is 211212220099. The reversal of 211212220091 is 190022212112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211212220091 is a prime.

It is a super-2 number, since 2×211212220091² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (211212220099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105606110045 + 105606110046.

It is an arithmetic number, because the mean of its divisors is an integer number (105606110046).

Almost surely, 2^211212220091 is an apocalyptic number.

211212220091 is a deficient number, since it is larger than the sum of its proper divisors (1).

211212220091 is an equidigital number, since it uses as much as digits as its factorization.

211212220091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The spelling of 211212220091 in words is "two hundred eleven billion, two hundred twelve million, two hundred twenty thousand, ninety-one".