1221100112 has 20 divisors (see below), whose sum is σ = 2374309716. Its totient is φ = 608375040.

The previous prime is 1221100063. The next prime is 1221100121. The reversal of 1221100112 is 2110011221.

It can be written as a sum of positive squares in 2 ways, for example, as 269747776 + 951352336 = 16424^2 + 30844^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1221100093 and 1221100102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131303 + ... + 140294.

Almost surely, 2^1221100112 is an apocalyptic number.

It is an amenable number.

1221100112 is a deficient number, since it is larger than the sum of its proper divisors (1153209604).

1221100112 is a wasteful number, since it uses less digits than its factorization.

1221100112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271886 (or 271880 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 1221100112 is about 34944.2429020862. The cubic root of 1221100112 is about 1068.8508091725.

Adding to 1221100112 its reverse (2110011221), we get a palindrome (3331111333).

The spelling of 1221100112 in words is "one billion, two hundred twenty-one million, one hundred thousand, one hundred twelve".