221111424721 has 16 divisors (see below), whose sum is σ = 242869248000. Its totient is φ = 199630386000.

The previous prime is 221111424707. The next prime is 221111424763. The reversal of 221111424721 is 127424111122.

It is a cyclic number.

It is not a de Polignac number, because 221111424721 - 2⁵ = 221111424689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221111424721.

It is not an unprimeable number, because it can be changed into a prime (221111424791) 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, 7957270 + ... + 7985008.

It is an arithmetic number, because the mean of its divisors is an integer number (15179328000).

Almost surely, 2^221111424721 is an apocalyptic number.

It is an amenable number.

221111424721 is a deficient number, since it is larger than the sum of its proper divisors (21757823279).

221111424721 is a wasteful number, since it uses less digits than its factorization.

221111424721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32700.

The product of its digits is 1792, while the sum is 28.

Adding to 221111424721 its reverse (127424111122), we get a palindrome (348535535843).

The spelling of 221111424721 in words is "two hundred twenty-one billion, one hundred eleven million, four hundred twenty-four thousand, seven hundred twenty-one".