1200212121221 has 8 divisors (see below), whose sum is σ = 1271129580504. Its totient is φ = 1129329856000.

The previous prime is 1200212121127. The next prime is 1200212121257. The reversal of 1200212121221 is 1221212120021.

It can be written as a sum of positive squares in 4 ways, for example, as 507671925121 + 692540196100 = 712511^2 + 832190^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1200212121221 - 2²⁶ = 1200145012357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1200212121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200212141221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8728280 + ... + 8864721.

It is an arithmetic number, because the mean of its divisors is an integer number (158891197563).

Almost surely, 2^{1200212121221} is an apocalyptic number.

It is an amenable number.

1200212121221 is a deficient number, since it is larger than the sum of its proper divisors (70917459283).

1200212121221 is a wasteful number, since it uses less digits than its factorization.

1200212121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17597031.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1200212121221 its reverse (1221212120021), we get a palindrome (2421424241242).

The spelling of 1200212121221 in words is "one trillion, two hundred billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".