21204703 has 12 divisors (see below), whose sum is σ = 24120040. Its totient is φ = 18480096.

The previous prime is 21204683. The next prime is 21204707. The reversal of 21204703 is 30740212.

It is a de Polignac number, because none of the positive numbers 2^k-21204703 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204707) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72225 + ... + 72517.

Almost surely, 2^21204703 is an apocalyptic number.

21204703 is a deficient number, since it is larger than the sum of its proper divisors (2915337).

21204703 is an equidigital number, since it uses as much as digits as its factorization.

21204703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 21204703 is about 4604.8564581320. The cubic root of 21204703 is about 276.7859650671.

Adding to 21204703 its reverse (30740212), we get a palindrome (51944915).

The spelling of 21204703 in words is "twenty-one million, two hundred four thousand, seven hundred three".