211221313 has 2 divisors, whose sum is σ = 211221314. Its totient is φ = 211221312.

The previous prime is 211221301. The next prime is 211221331. The reversal of 211221313 is 313122112.

Together with next prime (211221331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191213584 + 20007729 = 13828^2 + 4473^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211221313 is a prime.

It is a super-3 number, since 3×211221313³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (211221343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610656 + 105610657.

It is an arithmetic number, because the mean of its divisors is an integer number (105610657).

Almost surely, 2^211221313 is an apocalyptic number.

It is an amenable number.

211221313 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221313 is an equidigital number, since it uses as much as digits as its factorization.

211221313 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 72, while the sum is 16.

The square root of 211221313 is about 14533.4549574422. The cubic root of 211221313 is about 595.5422526496.

Adding to 211221313 its reverse (313122112), we get a palindrome (524343425).

The spelling of 211221313 in words is "two hundred eleven million, two hundred twenty-one thousand, three hundred thirteen".