221085295621 has 2 divisors, whose sum is σ = 221085295622. Its totient is φ = 221085295620.

The previous prime is 221085295619. The next prime is 221085295679. The reversal of 221085295621 is 126592580122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120874428900 + 100210866721 = 347670^2 + 316561^2 .

It is a cyclic number.

It is not a de Polignac number, because 221085295621 - 2¹ = 221085295619 is a prime.

Together with 221085295619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221085295601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110542647810 + 110542647811.

It is an arithmetic number, because the mean of its divisors is an integer number (110542647811).

Almost surely, 2^221085295621 is an apocalyptic number.

It is an amenable number.

221085295621 is a deficient number, since it is larger than the sum of its proper divisors (1).

221085295621 is an equidigital number, since it uses as much as digits as its factorization.

221085295621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 172800, while the sum is 43.

The spelling of 221085295621 in words is "two hundred twenty-one billion, eighty-five million, two hundred ninety-five thousand, six hundred twenty-one".