21303265 has 8 divisors (see below), whose sum is σ = 25672320. Its totient is φ = 16970352.

The previous prime is 21303259. The next prime is 21303283. The reversal of 21303265 is 56230312.

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 21303265 - 2³ = 21303257 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7719 + ... + 10108.

It is an arithmetic number, because the mean of its divisors is an integer number (3209040).

Almost surely, 2^21303265 is an apocalyptic number.

It is an amenable number.

21303265 is a deficient number, since it is larger than the sum of its proper divisors (4369055).

21303265 is a wasteful number, since it uses less digits than its factorization.

21303265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18071.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 21303265 is about 4615.5460132036. The cubic root of 21303265 is about 277.2141471124.

Adding to 21303265 its reverse (56230312), we get a palindrome (77533577).

The spelling of 21303265 in words is "twenty-one million, three hundred three thousand, two hundred sixty-five".