221121120019991 has 2 divisors, whose sum is σ = 221121120019992. Its totient is φ = 221121120019990.

The previous prime is 221121120019879. The next prime is 221121120020057. The reversal of 221121120019991 is 199910021121122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221121120019991 - 2³⁸ = 220846242113047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221121120019691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110560560009995 + 110560560009996.

It is an arithmetic number, because the mean of its divisors is an integer number (110560560009996).

Almost surely, 2^{221121120019991} is an apocalyptic number.

221121120019991 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121120019991 is an equidigital number, since it uses as much as digits as its factorization.

221121120019991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 41.

The spelling of 221121120019991 in words is "two hundred twenty-one trillion, one hundred twenty-one billion, one hundred twenty million, nineteen thousand, nine hundred ninety-one".