21328265 has 8 divisors (see below), whose sum is σ = 29250240. Its totient is φ = 14625072.

The previous prime is 21328247. The next prime is 21328273. The reversal of 21328265 is 56282312.

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

It is not a de Polignac number, because 21328265 - 2⁶ = 21328201 is a prime.

It is an unprimeable number.

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, 304655 + ... + 304724.

It is an arithmetic number, because the mean of its divisors is an integer number (3656280).

Almost surely, 2^21328265 is an apocalyptic number.

It is an amenable number.

21328265 is a deficient number, since it is larger than the sum of its proper divisors (7921975).

21328265 is an equidigital number, since it uses as much as digits as its factorization.

21328265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609391.

The product of its digits is 5760, while the sum is 29.

The square root of 21328265 is about 4618.2534577479. The cubic root of 21328265 is about 277.3225443378.

The spelling of 21328265 in words is "twenty-one million, three hundred twenty-eight thousand, two hundred sixty-five".