11123456621 has 2 divisors, whose sum is σ = 11123456622. Its totient is φ = 11123456620.

The previous prime is 11123456599. The next prime is 11123456683. The reversal of 11123456621 is 12665432111.

11123456621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6141073225 + 4982383396 = 78365^2 + 70586^2 .

It is a cyclic number.

It is not a de Polignac number, because 11123456621 - 2¹⁸ = 11123194477 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11123456221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5561728310 + 5561728311.

It is an arithmetic number, because the mean of its divisors is an integer number (5561728311).

Almost surely, 2^11123456621 is an apocalyptic number.

It is an amenable number.

11123456621 is a deficient number, since it is larger than the sum of its proper divisors (1).

11123456621 is an equidigital number, since it uses as much as digits as its factorization.

11123456621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 32.

Adding to 11123456621 its reverse (12665432111), we get a palindrome (23788888732).

The spelling of 11123456621 in words is "eleven billion, one hundred twenty-three million, four hundred fifty-six thousand, six hundred twenty-one".