221935697621 has 16 divisors (see below), whose sum is σ = 243016590528. Its totient is φ = 201006624000.

The previous prime is 221935697617. The next prime is 221935697671. The reversal of 221935697621 is 126796539122.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 221935697621 - 2² = 221935697617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221935697671) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4560011 + ... + 4608423.

It is an arithmetic number, because the mean of its divisors is an integer number (15188536908).

Almost surely, 2^221935697621 is an apocalyptic number.

It is an amenable number.

221935697621 is a deficient number, since it is larger than the sum of its proper divisors (21080892907).

221935697621 is a wasteful number, since it uses less digits than its factorization.

221935697621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49972.

The product of its digits is 2449440, while the sum is 53.

The spelling of 221935697621 in words is "two hundred twenty-one billion, nine hundred thirty-five million, six hundred ninety-seven thousand, six hundred twenty-one".