221421255546679 has 2 divisors, whose sum is σ = 221421255546680. Its totient is φ = 221421255546678.

The previous prime is 221421255546649. The next prime is 221421255546713. The reversal of 221421255546679 is 976645552124122.

221421255546679 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221421255546679 - 2³⁹ = 220871499732791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221421255546649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110710627773339 + 110710627773340.

It is an arithmetic number, because the mean of its divisors is an integer number (110710627773340).

Almost surely, 2^{221421255546679} is an apocalyptic number.

221421255546679 is a deficient number, since it is larger than the sum of its proper divisors (1).

221421255546679 is an equidigital number, since it uses as much as digits as its factorization.

221421255546679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576000, while the sum is 61.

The spelling of 221421255546679 in words is "two hundred twenty-one trillion, four hundred twenty-one billion, two hundred fifty-five million, five hundred forty-six thousand, six hundred seventy-nine".