221421253474991 has 2 divisors, whose sum is σ = 221421253474992. Its totient is φ = 221421253474990.

The previous prime is 221421253474979. The next prime is 221421253475011. The reversal of 221421253474991 is 199474352124122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221421253474991 - 2⁴² = 217023206963887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221421253473991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110710626737495 + 110710626737496.

It is an arithmetic number, because the mean of its divisors is an integer number (110710626737496).

Almost surely, 2^{221421253474991} is an apocalyptic number.

221421253474991 is a deficient number, since it is larger than the sum of its proper divisors (1).

221421253474991 is an equidigital number, since it uses as much as digits as its factorization.

221421253474991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8709120, while the sum is 56.

The spelling of 221421253474991 in words is "two hundred twenty-one trillion, four hundred twenty-one billion, two hundred fifty-three million, four hundred seventy-four thousand, nine hundred ninety-one".