1221444111 has 16 divisors (see below), whose sum is σ = 1711512704. Its totient is φ = 773859744.

The previous prime is 1221444109. The next prime is 1221444151. The reversal of 1221444111 is 1114441221.

It is not a de Polignac number, because 1221444111 - 2¹ = 1221444109 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 (1221444151) 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, 123181 + ... + 132726.

It is an arithmetic number, because the mean of its divisors is an integer number (106969544).

Almost surely, 2^1221444111 is an apocalyptic number.

1221444111 is a deficient number, since it is larger than the sum of its proper divisors (490068593).

1221444111 is a wasteful number, since it uses less digits than its factorization.

1221444111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255990.

The product of its digits is 256, while the sum is 21.

The square root of 1221444111 is about 34949.1646681291. The cubic root of 1221444111 is about 1068.9511692451.

Adding to 1221444111 its reverse (1114441221), we get a palindrome (2335885332).

The spelling of 1221444111 in words is "one billion, two hundred twenty-one million, four hundred forty-four thousand, one hundred eleven".