11145543221 has 2 divisors, whose sum is σ = 11145543222. Its totient is φ = 11145543220.

The previous prime is 11145543209. The next prime is 11145543223. The reversal of 11145543221 is 12234554111.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8927604196 + 2217939025 = 94486^2 + 47095^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11145543221 is a prime.

Together with 11145543223, 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 (11145543223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5572771610 + 5572771611.

It is an arithmetic number, because the mean of its divisors is an integer number (5572771611).

Almost surely, 2^11145543221 is an apocalyptic number.

It is an amenable number.

11145543221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11145543221 is an equidigital number, since it uses as much as digits as its factorization.

11145543221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4800, while the sum is 29.

The spelling of 11145543221 in words is "eleven billion, one hundred forty-five million, five hundred forty-three thousand, two hundred twenty-one".