21130403 has 4 divisors (see below), whose sum is σ = 24149040. Its totient is φ = 18111768.

The previous prime is 21130397. The next prime is 21130409. The reversal of 21130403 is 30403112.

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

It is an interprime number because it is at equal distance from previous prime (21130397) and next prime (21130409).

It is a cyclic number.

It is not a de Polignac number, because 21130403 - 2¹⁰ = 21129379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21130409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1509308 + ... + 1509321.

It is an arithmetic number, because the mean of its divisors is an integer number (6037260).

Almost surely, 2^21130403 is an apocalyptic number.

21130403 is a deficient number, since it is larger than the sum of its proper divisors (3018637).

21130403 is an equidigital number, since it uses as much as digits as its factorization.

21130403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3018636.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21130403 is about 4596.7818090486. The cubic root of 21130403 is about 276.4623063044.

Adding to 21130403 its reverse (30403112), we get a palindrome (51533515).

The spelling of 21130403 in words is "twenty-one million, one hundred thirty thousand, four hundred three".