1221321212 has 12 divisors (see below), whose sum is σ = 2150926680. Its totient is φ = 606770736.

The previous prime is 1221321203. The next prime is 1221321239. The reversal of 1221321212 is 2121231221.

It is a super-2 number, since 2×1221321212² = 2983251005762297888, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 971762 + ... + 973017.

It is an arithmetic number, because the mean of its divisors is an integer number (179243890).

Almost surely, 2^1221321212 is an apocalyptic number.

It is an amenable number.

1221321212 is a deficient number, since it is larger than the sum of its proper divisors (929605468).

1221321212 is a wasteful number, since it uses less digits than its factorization.

1221321212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1944940 (or 1944938 counting only the distinct ones).

The product of its digits is 96, while the sum is 17.

The square root of 1221321212 is about 34947.4063701443. The cubic root of 1221321212 is about 1068.9153162099.

Adding to 1221321212 its reverse (2121231221), we get a palindrome (3342552433).

The spelling of 1221321212 in words is "one billion, two hundred twenty-one million, three hundred twenty-one thousand, two hundred twelve".