22125821 has 2 divisors, whose sum is σ = 22125822. Its totient is φ = 22125820.

The previous prime is 22125809. The next prime is 22125841. The reversal of 22125821 is 12852122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17347225 + 4778596 = 4165^2 + 2186^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22125821 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 (22125841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11062910 + 11062911.

It is an arithmetic number, because the mean of its divisors is an integer number (11062911).

Almost surely, 2^22125821 is an apocalyptic number.

It is an amenable number.

22125821 is a deficient number, since it is larger than the sum of its proper divisors (1).

22125821 is an equidigital number, since it uses as much as digits as its factorization.

22125821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 640, while the sum is 23.

The square root of 22125821 is about 4703.8092010625. The cubic root of 22125821 is about 280.7370927835.

Adding to 22125821 its reverse (12852122), we get a palindrome (34977943).

The spelling of 22125821 in words is "twenty-two million, one hundred twenty-five thousand, eight hundred twenty-one".