21443413 has 4 divisors (see below), whose sum is σ = 22135168. Its totient is φ = 20751660.

The previous prime is 21443363. The next prime is 21443431. The reversal of 21443413 is 31434412.

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 21443413 - 2¹⁷ = 21312341 is a prime.

It is a super-2 number, since 2×21443413² = 919639922177138, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21443483) 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, 345831 + ... + 345892.

It is an arithmetic number, because the mean of its divisors is an integer number (5533792).

Almost surely, 2^21443413 is an apocalyptic number.

It is an amenable number.

21443413 is a deficient number, since it is larger than the sum of its proper divisors (691755).

21443413 is an equidigital number, since it uses as much as digits as its factorization.

21443413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 691754.

The product of its digits is 1152, while the sum is 22.

The square root of 21443413 is about 4630.7032943172. The cubic root of 21443413 is about 277.8207227055.

Adding to 21443413 its reverse (31434412), we get a palindrome (52877825).

Subtracting 21443413 from its reverse (31434412), we obtain a palindrome (9990999).

The spelling of 21443413 in words is "twenty-one million, four hundred forty-three thousand, four hundred thirteen".