1221311112 has 64 divisors (see below), whose sum is σ = 3570631680. Its totient is φ = 340828992.

The previous prime is 1221311111. The next prime is 1221311149. The reversal of 1221311112 is 2111131221.

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 1221311091 and 1221311100.

It is not an unprimeable number, because it can be changed into a prime (1221311111) 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, 77308 + ... + 91755.

It is an arithmetic number, because the mean of its divisors is an integer number (55791120).

Almost surely, 2^1221311112 is an apocalyptic number.

1221311112 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221311112 is an abundant number, since it is smaller than the sum of its proper divisors (2349320568).

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

1221311112 is a wasteful number, since it uses less digits than its factorization.

1221311112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169122 (or 169118 counting only the distinct ones).

The product of its digits is 24, while the sum is 15.

The square root of 1221311112 is about 34947.2618669904. The cubic root of 1221311112 is about 1068.9123696538.

Adding to 1221311112 its reverse (2111131221), we get a palindrome (3332442333).

The spelling of 1221311112 in words is "one billion, two hundred twenty-one million, three hundred eleven thousand, one hundred twelve".