1221203312 has 20 divisors (see below), whose sum is σ = 2704093296. Its totient is φ = 523372800.

The previous prime is 1221203309. The next prime is 1221203351. The reversal of 1221203312 is 2133021221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5451689 + ... + 5451912.

Almost surely, 2^1221203312 is an apocalyptic number.

It is an amenable number.

1221203312 is an abundant number, since it is smaller than the sum of its proper divisors (1482889984).

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

1221203312 is a wasteful number, since it uses less digits than its factorization.

1221203312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10903616 (or 10903610 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 1221203312 is about 34945.7195089756. The cubic root of 1221203312 is about 1068.8809192607.

Adding to 1221203312 its reverse (2133021221), we get a palindrome (3354224533).

The spelling of 1221203312 in words is "one billion, two hundred twenty-one million, two hundred three thousand, three hundred twelve".