11011221221 has 32 divisors (see below), whose sum is σ = 15562444800. Its totient is φ = 7503295680.

The previous prime is 11011221191. The next prime is 11011221229. The reversal of 11011221221 is 12212211011.

It is a cyclic number.

It is not a de Polignac number, because 11011221221 - 2²⁶ = 10944112357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11011221196 and 11011221205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11011221229) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 270461 + ... + 308498.

It is an arithmetic number, because the mean of its divisors is an integer number (486326400).

Almost surely, 2^11011221221 is an apocalyptic number.

11011221221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11011221221 is a deficient number, since it is larger than the sum of its proper divisors (4551223579).

11011221221 is a wasteful number, since it uses less digits than its factorization.

11011221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579009.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 11011221221 its reverse (12212211011), we get a palindrome (23223432232).

It can be divided in two parts, 11011 and 221221, that added together give a palindrome (232232).

The spelling of 11011221221 in words is "eleven billion, eleven million, two hundred twenty-one thousand, two hundred twenty-one".