21084359 has 4 divisors (see below), whose sum is σ = 21136320. Its totient is φ = 21032400.

The previous prime is 21084317. The next prime is 21084377. The reversal of 21084359 is 95348012.

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 21084359 - 2⁸ = 21084103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21084379) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25367 + ... + 26184.

It is an arithmetic number, because the mean of its divisors is an integer number (5284080).

Almost surely, 2^21084359 is an apocalyptic number.

21084359 is a deficient number, since it is larger than the sum of its proper divisors (51961).

21084359 is an equidigital number, since it uses as much as digits as its factorization.

21084359 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51960.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 21084359 is about 4591.7707913179. The cubic root of 21084359 is about 276.2613527681.

The spelling of 21084359 in words is "twenty-one million, eighty-four thousand, three hundred fifty-nine".