11211221122221 has 4 divisors (see below), whose sum is σ = 14948294829632. Its totient is φ = 7474147414812.

The previous prime is 11211221122219. The next prime is 11211221122271. The reversal of 11211221122221 is 12222112211211.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 11211221122221 - 2¹ = 11211221122219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211221122271) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1868536853701 + ... + 1868536853706.

It is an arithmetic number, because the mean of its divisors is an integer number (3737073707408).

Almost surely, 2^{11211221122221} is an apocalyptic number.

It is an amenable number.

11211221122221 is a deficient number, since it is larger than the sum of its proper divisors (3737073707411).

11211221122221 is an equidigital number, since it uses as much as digits as its factorization.

11211221122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3737073707410.

The product of its digits is 128, while the sum is 21.

Adding to 11211221122221 its reverse (12222112211211), we get a palindrome (23433333333432).

The spelling of 11211221122221 in words is "eleven trillion, two hundred eleven billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".