11221221221 has 8 divisors (see below), whose sum is σ = 12956462400. Its totient is φ = 9519032448.

The previous prime is 11221221217. The next prime is 11221221233. The reversal of 11221221221 is 12212212211.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11221221221 - 2² = 11221221217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11221221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11221221241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8262371 + ... + 8263728.

It is an arithmetic number, because the mean of its divisors is an integer number (1619557800).

Almost surely, 2^11221221221 is an apocalyptic number.

It is an amenable number.

11221221221 is a deficient number, since it is larger than the sum of its proper divisors (1735241179).

11221221221 is an equidigital number, since it uses as much as digits as its factorization.

11221221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16526203.

The product of its digits is 64, while the sum is 17.

Adding to 11221221221 its reverse (12212212211), we get a palindrome (23433433432).

The spelling of 11221221221 in words is "eleven billion, two hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".