1221201212 has 144 divisors (see below), whose sum is σ = 2881482240. Its totient is φ = 441936000.

The previous prime is 1221201211. The next prime is 1221201217. The reversal of 1221201212 is 2121021221.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221201211) 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 47 ways as a sum of consecutive naturals, for example, 3926537 + ... + 3926847.

Almost surely, 2^1221201212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221201212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1440741120).

1221201212 is an abundant number, since it is smaller than the sum of its proper divisors (1660281028).

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

1221201212 is a wasteful number, since it uses less digits than its factorization.

1221201212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 1221201212 is about 34945.6894623643. The cubic root of 1221201212 is about 1068.8803065723.

Adding to 1221201212 its reverse (2121021221), we get a palindrome (3342222433).

Subtracting 1221201212 from its reverse (2121021221), we obtain a square (899820009 = 29997²).

The spelling of 1221201212 in words is "one billion, two hundred twenty-one million, two hundred one thousand, two hundred twelve".