1221311100112 has 20 divisors (see below), whose sum is σ = 2366311911300. Its totient is φ = 610649961728.

The previous prime is 1221311100103. The next prime is 1221311100137. The reversal of 1221311100112 is 2110011131221.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 674592824896 + 546718275216 = 821336^2 + 739404^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1888014 + ... + 2450962.

It is an arithmetic number, because the mean of its divisors is an integer number (118315595565).

Almost surely, 2^{1221311100112} is an apocalyptic number.

It is an amenable number.

1221311100112 is a deficient number, since it is larger than the sum of its proper divisors (1145000811188).

1221311100112 is a wasteful number, since it uses less digits than its factorization.

1221311100112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698550 (or 698544 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 16.

Adding to 1221311100112 its reverse (2110011131221), we get a palindrome (3331322231333).

The spelling of 1221311100112 in words is "one trillion, two hundred twenty-one billion, three hundred eleven million, one hundred thousand, one hundred twelve".