21260717 has 8 divisors (see below), whose sum is σ = 22467840. Its totient is φ = 20077200.

The previous prime is 21260711. The next prime is 21260749. The reversal of 21260717 is 71706212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21260717 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21260711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4034 + ... + 7667.

It is an arithmetic number, because the mean of its divisors is an integer number (2808480).

Almost surely, 2^21260717 is an apocalyptic number.

It is an amenable number.

21260717 is a deficient number, since it is larger than the sum of its proper divisors (1207123).

21260717 is a wasteful number, since it uses less digits than its factorization.

21260717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11803.

The product of its (nonzero) digits is 1176, while the sum is 26.

The square root of 21260717 is about 4610.9345039807. The cubic root of 21260717 is about 277.0294685553.

Adding to 21260717 its reverse (71706212), we get a palindrome (92966929).

The spelling of 21260717 in words is "twenty-one million, two hundred sixty thousand, seven hundred seventeen".