21442413 has 4 divisors (see below), whose sum is σ = 28589888. Its totient is φ = 14294940.

The previous prime is 21442411. The next prime is 21442427. The reversal of 21442413 is 31424412.

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 not a de Polignac number, because 21442413 - 2¹ = 21442411 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21442413.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442411) 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, 3573733 + ... + 3573738.

It is an arithmetic number, because the mean of its divisors is an integer number (7147472).

Almost surely, 2^21442413 is an apocalyptic number.

It is an amenable number.

21442413 is a deficient number, since it is larger than the sum of its proper divisors (7147475).

21442413 is an equidigital number, since it uses as much as digits as its factorization.

21442413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7147474.

The product of its digits is 768, while the sum is 21.

The square root of 21442413 is about 4630.5953180990. The cubic root of 21442413 is about 277.8164039738.

Adding to 21442413 its reverse (31424412), we get a palindrome (52866825).

The spelling of 21442413 in words is "twenty-one million, four hundred forty-two thousand, four hundred thirteen".