11101212221 has 16 divisors (see below), whose sum is σ = 12156595776. Its totient is φ = 10053600000.

The previous prime is 11101212181. The next prime is 11101212247. The reversal of 11101212221 is 12221210111.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11101212221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11101212196 and 11101212205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11101212271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5208326 + ... + 5210456.

It is an arithmetic number, because the mean of its divisors is an integer number (759787236).

Almost surely, 2^11101212221 is an apocalyptic number.

11101212221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11101212221 is a deficient number, since it is larger than the sum of its proper divisors (1055383555).

11101212221 is a wasteful number, since it uses less digits than its factorization.

11101212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3724.

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

Adding to 11101212221 its reverse (12221210111), we get a palindrome (23322422332).

It can be divided in two parts, 11101 and 212221, that added together give a palindrome (223322).

The spelling of 11101212221 in words is "eleven billion, one hundred one million, two hundred twelve thousand, two hundred twenty-one".