11111201221 has 4 divisors (see below), whose sum is σ = 11160149472. Its totient is φ = 11062252972.

The previous prime is 11111201219. The next prime is 11111201237. The reversal of 11111201221 is 12210211111.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 11111201221 - 2¹ = 11111201219 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 (11111231221) 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, 24473785 + ... + 24474238.

It is an arithmetic number, because the mean of its divisors is an integer number (2790037368).

Almost surely, 2^11111201221 is an apocalyptic number.

It is an amenable number.

11111201221 is a deficient number, since it is larger than the sum of its proper divisors (48948251).

11111201221 is an equidigital number, since it uses as much as digits as its factorization.

11111201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48948250.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 11111201221 its reverse (12210211111), we get a palindrome (23321412332).

The spelling of 11111201221 in words is "eleven billion, one hundred eleven million, two hundred one thousand, two hundred twenty-one".