21260506 has 16 divisors (see below), whose sum is σ = 35544960. Its totient is φ = 9478080.

The previous prime is 21260501. The next prime is 21260521. The reversal of 21260506 is 60506212.

It is not an unprimeable number, because it can be changed into a prime (21260501) 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, 15810 + ... + 17101.

It is an arithmetic number, because the mean of its divisors is an integer number (2221560).

Almost surely, 2^21260506 is an apocalyptic number.

21260506 is a deficient number, since it is larger than the sum of its proper divisors (14284454).

21260506 is a wasteful number, since it uses less digits than its factorization.

21260506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32949.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21260506 is about 4610.9116235296. The cubic root of 21260506 is about 277.0285521012.

Adding to 21260506 its reverse (60506212), we get a palindrome (81766718).

The spelling of 21260506 in words is "twenty-one million, two hundred sixty thousand, five hundred six".