11010111221 has 2 divisors, whose sum is σ = 11010111222. Its totient is φ = 11010111220.

The previous prime is 11010111181. The next prime is 11010111223. The reversal of 11010111221 is 12211101011.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6803940196 + 4206171025 = 82486^2 + 64855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11010111221 is a prime.

It is a super-2 number, since 2×11010111221² (a number of 21 digits) contains 22 as substring.

Together with 11010111223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11010111223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5505055610 + 5505055611.

It is an arithmetic number, because the mean of its divisors is an integer number (5505055611).

Almost surely, 2^11010111221 is an apocalyptic number.

It is an amenable number.

11010111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11010111221 is an equidigital number, since it uses as much as digits as its factorization.

11010111221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 11010111221 its reverse (12211101011), we get a palindrome (23221212232).

It can be divided in two parts, 1101011 and 1221, that multiplied together give a palindrome (1344334431).

The spelling of 11010111221 in words is "eleven billion, ten million, one hundred eleven thousand, two hundred twenty-one".