21412403 has 4 divisors (see below), whose sum is σ = 21763488. Its totient is φ = 21061320.

The previous prime is 21412387. The next prime is 21412429. The reversal of 21412403 is 30421412.

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 21412403 - 2⁴ = 21412387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21412493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 175451 + ... + 175572.

It is an arithmetic number, because the mean of its divisors is an integer number (5440872).

Almost surely, 2^21412403 is an apocalyptic number.

21412403 is a deficient number, since it is larger than the sum of its proper divisors (351085).

21412403 is an equidigital number, since it uses as much as digits as its factorization.

21412403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351084.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21412403 is about 4627.3537794294. The cubic root of 21412403 is about 277.6867363097.

Adding to 21412403 its reverse (30421412), we get a palindrome (51833815).

Subtracting 21412403 from its reverse (30421412), we obtain a palindrome (9009009).

The spelling of 21412403 in words is "twenty-one million, four hundred twelve thousand, four hundred three".