1221111444 has 48 divisors (see below), whose sum is σ = 3344313728. Its totient is φ = 339458688.

The previous prime is 1221111433. The next prime is 1221111449. The reversal of 1221111444 is 4441111221.

It is a super-2 number, since 2×1221111444² = 2982226317335530272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1221111444.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221111449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 193339 + ... + 199554.

Almost surely, 2^1221111444 is an apocalyptic number.

1221111444 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1221111444 is an abundant number, since it is smaller than the sum of its proper divisors (2123202284).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221111444 is a wasteful number, since it uses less digits than its factorization.

1221111444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392944 (or 392942 counting only the distinct ones).

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

The square root of 1221111444 is about 34944.4050457294. The cubic root of 1221111444 is about 1068.8541155298.

Adding to 1221111444 its reverse (4441111221), we get a palindrome (5662222665).

The spelling of 1221111444 in words is "one billion, two hundred twenty-one million, one hundred eleven thousand, four hundred forty-four".