1221111112 has 32 divisors (see below), whose sum is σ = 2469458880. Its totient is φ = 562731840.

The previous prime is 1221111097. The next prime is 1221111167. The reversal of 1221111112 is 2111111221.

It is a happy number.

It is a super-2 number, since 2×1221111112² = 2982224695699753088, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

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 = 1221111092 and 1221111101.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62437 + ... + 79627.

It is an arithmetic number, because the mean of its divisors is an integer number (77170590).

Almost surely, 2^1221111112 is an apocalyptic number.

It is an amenable number.

1221111112 is an abundant number, since it is smaller than the sum of its proper divisors (1248347768).

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

1221111112 is a wasteful number, since it uses less digits than its factorization.

1221111112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17893 (or 17889 counting only the distinct ones).

The product of its digits is 8, while the sum is 13.

The square root of 1221111112 is about 34944.4002953263. The cubic root of 1221111112 is about 1068.8540186619.

Adding to 1221111112 its reverse (2111111221), we get a palindrome (3332222333).

The spelling of 1221111112 in words is "one billion, two hundred twenty-one million, one hundred eleven thousand, one hundred twelve".