2221211999891 has 2 divisors, whose sum is σ = 2221211999892. Its totient is φ = 2221211999890.

The previous prime is 2221211999887. The next prime is 2221212000011. The reversal of 2221211999891 is 1989991121222.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2221211999891 - 2² = 2221211999887 is a prime.

It is not a weakly prime, because it can be changed into another prime (2221211992891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110605999945 + 1110605999946.

It is an arithmetic number, because the mean of its divisors is an integer number (1110605999946).

Almost surely, 2^{2221211999891} is an apocalyptic number.

2221211999891 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221211999891 is an equidigital number, since it uses as much as digits as its factorization.

2221211999891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 56.

The spelling of 2221211999891 in words is "two trillion, two hundred twenty-one billion, two hundred eleven million, nine hundred ninety-nine thousand, eight hundred ninety-one".