21064223 has 4 divisors (see below), whose sum is σ = 21352848. Its totient is φ = 20775600.

The previous prime is 21064193. The next prime is 21064231. The reversal of 21064223 is 32246012.

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 21064223 - 2¹⁰ = 21063199 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21064195 and 21064204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21064273) 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, 144203 + ... + 144348.

It is an arithmetic number, because the mean of its divisors is an integer number (5338212).

Almost surely, 2^21064223 is an apocalyptic number.

21064223 is a deficient number, since it is larger than the sum of its proper divisors (288625).

21064223 is an equidigital number, since it uses as much as digits as its factorization.

21064223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288624.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 21064223 is about 4589.5776494139. The cubic root of 21064223 is about 276.1733796502.

The spelling of 21064223 in words is "twenty-one million, sixty-four thousand, two hundred twenty-three".