21412813 has 4 divisors (see below), whose sum is σ = 21433600. Its totient is φ = 21392028.

The previous prime is 21412801. The next prime is 21412823. The reversal of 21412813 is 31821412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21412813 - 2⁹ = 21412301 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21412823) 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, 8763 + ... + 10936.

It is an arithmetic number, because the mean of its divisors is an integer number (5358400).

Almost surely, 2^21412813 is an apocalyptic number.

It is an amenable number.

21412813 is a deficient number, since it is larger than the sum of its proper divisors (20787).

21412813 is a wasteful number, since it uses less digits than its factorization.

21412813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20786.

The product of its digits is 384, while the sum is 22.

The square root of 21412813 is about 4627.3980809954. The cubic root of 21412813 is about 277.6885086599.

The spelling of 21412813 in words is "twenty-one million, four hundred twelve thousand, eight hundred thirteen".