1221312323200 has 96 divisors (see below), whose sum is σ = 3027762064620. Its totient is φ = 486786048000.

The previous prime is 1221312323159. The next prime is 1221312323249. The reversal of 1221312323200 is 23232131221.

It can be written as a sum of positive squares in 6 ways, for example, as 823171514944 + 398140808256 = 907288^2 + 630984^2 .

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 11 ways as a sum of consecutive naturals, for example, 220090 + ... + 1578310.

Almost surely, 2^{1221312323200} is an apocalyptic number.

1221312323200 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 1221312323200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1513881032310).

1221312323200 is an abundant number, since it is smaller than the sum of its proper divisors (1806449741420).

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

1221312323200 is a wasteful number, since it uses less digits than its factorization.

1221312323200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1358526 (or 1358509 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 1221312323200 its reverse (23232131221), we get a palindrome (1244544454421).

The spelling of 1221312323200 in words is "one trillion, two hundred twenty-one billion, three hundred twelve million, three hundred twenty-three thousand, two hundred".