1211222220012 has 144 divisors (see below), whose sum is σ = 3617778964800. Its totient is φ = 334450238976.

The previous prime is 1211222219983. The next prime is 1211222220023. The reversal of 1211222220012 is 2100222221121.

It is a happy number.

1211222220012 is a `hidden beast` number, since 1 + 211 + 222 + 220 + 0 + 12 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 953358 + ... + 1825194.

Almost surely, 2^{1211222220012} is an apocalyptic number.

1211222220012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211222220012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1808889482400).

1211222220012 is an abundant number, since it is smaller than the sum of its proper divisors (2406556744788).

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

1211222220012 is a wasteful number, since it uses less digits than its factorization.

1211222220012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872040 (or 872035 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1211222220012 its reverse (2100222221121), we get a palindrome (3311444441133).

The spelling of 1211222220012 in words is "one trillion, two hundred eleven billion, two hundred twenty-two million, two hundred twenty thousand, twelve".