21260221 has 8 divisors (see below), whose sum is σ = 22467200. Its totient is φ = 20062080.

The previous prime is 21260209. The next prime is 21260227. The reversal of 21260221 is 12206212.

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

It is a cyclic number.

It is not a de Polignac number, because 21260221 - 2⁹ = 21259709 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 21260195 and 21260204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21260227) 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, 3085 + ... + 7213.

It is an arithmetic number, because the mean of its divisors is an integer number (2808400).

Almost surely, 2^21260221 is an apocalyptic number.

It is an amenable number.

21260221 is a deficient number, since it is larger than the sum of its proper divisors (1206979).

21260221 is a wasteful number, since it uses less digits than its factorization.

21260221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4419.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21260221 is about 4610.8807184745. The cubic root of 21260221 is about 277.0273142271.

Adding to 21260221 its reverse (12206212), we get a palindrome (33466433).

The spelling of 21260221 in words is "twenty-one million, two hundred sixty thousand, two hundred twenty-one".