11215209221 has 2 divisors, whose sum is σ = 11215209222. Its totient is φ = 11215209220.

The previous prime is 11215209209. The next prime is 11215209241. The reversal of 11215209221 is 12290251211.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10912936225 + 302272996 = 104465^2 + 17386^2 .

It is a cyclic number.

It is not a de Polignac number, because 11215209221 - 2²⁶ = 11148100357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11215209241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5607604610 + 5607604611.

It is an arithmetic number, because the mean of its divisors is an integer number (5607604611).

Almost surely, 2^11215209221 is an apocalyptic number.

It is an amenable number.

11215209221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11215209221 is an equidigital number, since it uses as much as digits as its factorization.

11215209221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 26.

The spelling of 11215209221 in words is "eleven billion, two hundred fifteen million, two hundred nine thousand, two hundred twenty-one".