211221013 has 2 divisors, whose sum is σ = 211221014. Its totient is φ = 211221012.

The previous prime is 211220993. The next prime is 211221037. The reversal of 211221013 is 310122112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 109977169 + 101243844 = 10487^2 + 10062^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221013 - 2⁵ = 211220981 is a prime.

It is a super-2 number, since 2×211221013² = 89228632665492338, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211220984 and 211221002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211221313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105610506 + 105610507.

It is an arithmetic number, because the mean of its divisors is an integer number (105610507).

Almost surely, 2^211221013 is an apocalyptic number.

It is an amenable number.

211221013 is a deficient number, since it is larger than the sum of its proper divisors (1).

211221013 is an equidigital number, since it uses as much as digits as its factorization.

211221013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 211221013 is about 14533.4446364239. Note that the first 3 decimals coincide. The cubic root of 211221013 is about 595.5419706977.

Adding to 211221013 its reverse (310122112), we get a palindrome (521343125).

The spelling of 211221013 in words is "two hundred eleven million, two hundred twenty-one thousand, thirteen".