221121111136665 has 16 divisors (see below), whose sum is σ = 353795605282368. Its totient is φ = 117930650118336.

The previous prime is 221121111136577. The next prime is 221121111136691. The reversal of 221121111136665 is 566631111121122.

It is not a de Polignac number, because 221121111136665 - 2⁷ = 221121111136537 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35063719 + ... + 40886508.

It is an arithmetic number, because the mean of its divisors is an integer number (22112225330148).

Almost surely, 2^{221121111136665} is an apocalyptic number.

It is an amenable number.

221121111136665 is a deficient number, since it is larger than the sum of its proper divisors (132674494145703).

221121111136665 is a wasteful number, since it uses less digits than its factorization.

221121111136665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76144328.

The product of its digits is 25920, while the sum is 39.

Adding to 221121111136665 its reverse (566631111121122), we get a palindrome (787752222257787).

The spelling of 221121111136665 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-five".