1221122212000 has 96 divisors (see below), whose sum is σ = 3001552379280. Its totient is φ = 488244556800.

The previous prime is 1221122211979. The next prime is 1221122212003. The reversal of 1221122212000 is 2122211221.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 325169095696 + 895953116304 = 570236^2 + 946548^2 .

It is a super-2 number, since 2×1221122212000² (a number of 25 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (1221122212003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9685366 + ... + 9810634.

Almost surely, 2^{1221122212000} is an apocalyptic number.

1221122212000 is a gapful number since it is divisible by the number (10) 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 1221122212000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1500776189640).

1221122212000 is an abundant number, since it is smaller than the sum of its proper divisors (1780430167280).

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

1221122212000 is a wasteful number, since it uses less digits than its factorization.

1221122212000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127731 (or 127713 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221122212000 its reverse (2122211221), we get a palindrome (1223244423221).

The spelling of 1221122212000 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-two million, two hundred twelve thousand".