221121111136664 has 128 divisors (see below), whose sum is σ = 440926258544640. Its totient is φ = 103738721404032.

The previous prime is 221121111136577. The next prime is 221121111136691. The reversal of 221121111136664 is 466631111121122.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9360404357 + ... + 9360427979.

It is an arithmetic number, because the mean of its divisors is an integer number (3444736394880).

Almost surely, 2^{221121111136664} is an apocalyptic number.

It is an amenable number.

221121111136664 is a deficient number, since it is larger than the sum of its proper divisors (219805147407976).

221121111136664 is a wasteful number, since it uses less digits than its factorization.

221121111136664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26869 (or 26865 counting only the distinct ones).

The product of its digits is 20736, while the sum is 38.

Adding to 221121111136664 its reverse (466631111121122), we get a palindrome (687752222257786).

The spelling of 221121111136664 in words is "two hundred twenty-one trillion, one hundred twenty-one billion, one hundred eleven million, one hundred thirty-six thousand, six hundred sixty-four".