1221222021200 has 30 divisors (see below), whose sum is σ = 2933985906894. Its totient is φ = 488488808320.

The previous prime is 1221222021197. The next prime is 1221222021209. The reversal of 1221222021200 is 21202221221.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 409171984 + 1220812849216 = 20228^2 + 1104904^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221222021209) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1526527127 + ... + 1526527926.

Almost surely, 2^{1221222021200} is an apocalyptic number.

1221222021200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221222021200 is an abundant number, since it is smaller than the sum of its proper divisors (1712763885694).

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

1221222021200 is a wasteful number, since it uses less digits than its factorization.

1221222021200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3053055071 (or 3053055060 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 1221222021200 its reverse (21202221221), we get a palindrome (1242424242421).

The spelling of 1221222021200 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two million, twenty-one thousand, two hundred".