21230617 has 2 divisors, whose sum is σ = 21230618. Its totient is φ = 21230616.

The previous prime is 21230611. The next prime is 21230641. The reversal of 21230617 is 71603212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11964681 + 9265936 = 3459^2 + 3044^2 .

It is a cyclic number.

It is not a de Polignac number, because 21230617 - 2¹¹ = 21228569 is a prime.

It is not a weakly prime, because it can be changed into another prime (21230611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615308 + 10615309.

It is an arithmetic number, because the mean of its divisors is an integer number (10615309).

Almost surely, 2^21230617 is an apocalyptic number.

It is an amenable number.

21230617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230617 is an equidigital number, since it uses as much as digits as its factorization.

21230617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 21230617 is about 4607.6693674785. The cubic root of 21230617 is about 276.8986713792.

Adding to 21230617 its reverse (71603212), we get a palindrome (92833829).

The spelling of 21230617 in words is "twenty-one million, two hundred thirty thousand, six hundred seventeen".