1213211321 has 16 divisors (see below), whose sum is σ = 1401093120. Its totient is φ = 1029021840.

The previous prime is 1213211297. The next prime is 1213211323. The reversal of 1213211321 is 1231123121.

It is a de Polignac number, because none of the positive numbers 2^k-1213211321 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1213211321.

It is not an unprimeable number, because it can be changed into a prime (1213211323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320180 + ... + 323946.

It is an arithmetic number, because the mean of its divisors is an integer number (87568320).

Almost surely, 2^1213211321 is an apocalyptic number.

It is an amenable number.

1213211321 is a deficient number, since it is larger than the sum of its proper divisors (187881799).

1213211321 is a wasteful number, since it uses less digits than its factorization.

1213211321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4244.

The product of its digits is 72, while the sum is 17.

The square root of 1213211321 is about 34831.1831696829. The cubic root of 1213211321 is about 1066.5441012275.

Adding to 1213211321 its reverse (1231123121), we get a palindrome (2444334442).

The spelling of 1213211321 in words is "one billion, two hundred thirteen million, two hundred eleven thousand, three hundred twenty-one".