1221131444 has 48 divisors (see below), whose sum is σ = 2455817280. Its totient is φ = 526590720.

The previous prime is 1221131423. The next prime is 1221131453. The reversal of 1221131444 is 4441311221.

It is a congruent number.

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, 63659 + ... + 80589.

It is an arithmetic number, because the mean of its divisors is an integer number (51162860).

Almost surely, 2^1221131444 is an apocalyptic number.

It is an amenable number.

1221131444 is an abundant number, since it is smaller than the sum of its proper divisors (1234685836).

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

1221131444 is a wasteful number, since it uses less digits than its factorization.

1221131444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17040 (or 17038 counting only the distinct ones).

The product of its digits is 768, while the sum is 23.

The square root of 1221131444 is about 34944.6912134018. The cubic root of 1221131444 is about 1068.8599509146.

Adding to 1221131444 its reverse (4441311221), we get a palindrome (5662442665).

The spelling of 1221131444 in words is "one billion, two hundred twenty-one million, one hundred thirty-one thousand, four hundred forty-four".