21338015 has 4 divisors (see below), whose sum is σ = 25605624. Its totient is φ = 17070408.

The previous prime is 21338003. The next prime is 21338039. The reversal of 21338015 is 51083312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21338015 - 2⁸ = 21337759 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2133797 + ... + 2133806.

It is an arithmetic number, because the mean of its divisors is an integer number (6401406).

Almost surely, 2^21338015 is an apocalyptic number.

21338015 is a deficient number, since it is larger than the sum of its proper divisors (4267609).

21338015 is an equidigital number, since it uses as much as digits as its factorization.

21338015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4267608.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21338015 is about 4619.3089309982. The cubic root of 21338015 is about 277.3647962961.

The spelling of 21338015 in words is "twenty-one million, three hundred thirty-eight thousand, fifteen".