221211200891 has 2 divisors, whose sum is σ = 221211200892. Its totient is φ = 221211200890.

The previous prime is 221211200849. The next prime is 221211200893. The reversal of 221211200891 is 198002112122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221211200891 - 2⁶ = 221211200827 is a prime.

Together with 221211200893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221211200893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605600445 + 110605600446.

It is an arithmetic number, because the mean of its divisors is an integer number (110605600446).

Almost surely, 2^221211200891 is an apocalyptic number.

221211200891 is a deficient number, since it is larger than the sum of its proper divisors (1).

221211200891 is an equidigital number, since it uses as much as digits as its factorization.

221211200891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 29.

The spelling of 221211200891 in words is "two hundred twenty-one billion, two hundred eleven million, two hundred thousand, eight hundred ninety-one".