21430205 has 8 divisors (see below), whose sum is σ = 25746432. Its totient is φ = 17124048.

The previous prime is 21430193. The next prime is 21430229. The reversal of 21430205 is 50203412.

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 21430205 - 2¹⁰ = 21429181 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 7 ways as a sum of consecutive naturals, for example, 3464 + ... + 7406.

It is an arithmetic number, because the mean of its divisors is an integer number (3218304).

Almost surely, 2^21430205 is an apocalyptic number.

It is an amenable number.

21430205 is a deficient number, since it is larger than the sum of its proper divisors (4316227).

21430205 is a wasteful number, since it uses less digits than its factorization.

21430205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5035.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 21430205 is about 4629.2769413808. The cubic root of 21430205 is about 277.7636700687.

Adding to 21430205 its reverse (50203412), we get a palindrome (71633617).

The spelling of 21430205 in words is "twenty-one million, four hundred thirty thousand, two hundred five".