21130203 has 4 divisors (see below), whose sum is σ = 28173608. Its totient is φ = 14086800.

The previous prime is 21130111. The next prime is 21130231. The reversal of 21130203 is 30203112.

It is a happy number.

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

It is not a de Polignac number, because 21130203 - 2⁸ = 21129947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21150203) 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, 3521698 + ... + 3521703.

It is an arithmetic number, because the mean of its divisors is an integer number (7043402).

Almost surely, 2^21130203 is an apocalyptic number.

21130203 is a deficient number, since it is larger than the sum of its proper divisors (7043405).

21130203 is an equidigital number, since it uses as much as digits as its factorization.

21130203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7043404.

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 21130203 is about 4596.7600546472. The cubic root of 21130203 is about 276.4614340599.

Adding to 21130203 its reverse (30203112), we get a palindrome (51333315).

The spelling of 21130203 in words is "twenty-one million, one hundred thirty thousand, two hundred three".