21260530 has 16 divisors (see below), whose sum is σ = 38326680. Its totient is φ = 8491392.

The previous prime is 21260527. The next prime is 21260531. The reversal of 21260530 is 3506212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 5650129 + 15610401 = 2377^2 + 3951^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21260498 and 21260507.

It is not an unprimeable number, because it can be changed into a prime (21260531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8236 + ... + 10504.

Almost surely, 2^21260530 is an apocalyptic number.

21260530 is a deficient number, since it is larger than the sum of its proper divisors (17066150).

21260530 is a wasteful number, since it uses less digits than its factorization.

21260530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3213.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 21260530 is about 4610.9142260511. The cubic root of 21260530 is about 277.0286563428.

Adding to 21260530 its reverse (3506212), we get a palindrome (24766742).

The spelling of 21260530 in words is "twenty-one million, two hundred sixty thousand, five hundred thirty".