1211221100012 has 192 divisors, whose sum is σ = 2881726848000. Its totient is φ = 431043379200.

The previous prime is 1211221099981. The next prime is 1211221100053. The reversal of 1211221100012 is 2100011221121.

It is a super-2 number, since 2×1211221100012² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a self number, because there is not a number n which added to its sum of digits gives 1211221100012.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 130500812 + ... + 130510092.

It is an arithmetic number, because the mean of its divisors is an integer number (15008994000).

Almost surely, 2^{1211221100012} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211221100012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1440863424000).

1211221100012 is an abundant number, since it is smaller than the sum of its proper divisors (1670505747988).

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

1211221100012 is a wasteful number, since it uses less digits than its factorization.

1211221100012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10120 (or 10118 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1211221100012 its reverse (2100011221121), we get a palindrome (3311232321133).

The spelling of 1211221100012 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred thousand, twelve".