21430203 has 4 divisors (see below), whose sum is σ = 28573608. Its totient is φ = 14286800.

The previous prime is 21430193. The next prime is 21430229. The reversal of 21430203 is 30203412.

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 21430203 - 2⁶ = 21430139 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21430103) 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, 3571698 + ... + 3571703.

It is an arithmetic number, because the mean of its divisors is an integer number (7143402).

Almost surely, 2^21430203 is an apocalyptic number.

21430203 is a deficient number, since it is larger than the sum of its proper divisors (7143405).

21430203 is an equidigital number, since it uses as much as digits as its factorization.

21430203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7143404.

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21430203 is about 4629.2767253643. The cubic root of 21430203 is about 277.7636614278.

Adding to 21430203 its reverse (30203412), we get a palindrome (51633615).

The spelling of 21430203 in words is "twenty-one million, four hundred thirty thousand, two hundred three".