22666621 has 2 divisors, whose sum is σ = 22666622. Its totient is φ = 22666620.

The previous prime is 22666619. The next prime is 22666663. The reversal of 22666621 is 12666622.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14175225 + 8491396 = 3765^2 + 2914^2 .

It is a cyclic number.

It is not a de Polignac number, because 22666621 - 2¹ = 22666619 is a prime.

Together with 22666619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22666691) 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, 11333310 + 11333311.

It is an arithmetic number, because the mean of its divisors is an integer number (11333311).

Almost surely, 2^22666621 is an apocalyptic number.

It is an amenable number.

22666621 is a deficient number, since it is larger than the sum of its proper divisors (1).

22666621 is an equidigital number, since it uses as much as digits as its factorization.

22666621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 31.

The square root of 22666621 is about 4760.9474897335. The cubic root of 22666621 is about 283.0059682343.

Subtracting from 22666621 its reverse (12666622), we obtain a palindrome (9999999).

The spelling of 22666621 in words is "twenty-two million, six hundred sixty-six thousand, six hundred twenty-one".