21443313 has 8 divisors (see below), whose sum is σ = 29363968. Its totient is φ = 13909104.

The previous prime is 21443311. The next prime is 21443321. The reversal of 21443313 is 31334412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21443313 - 2¹ = 21443311 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 21443313.

It is not an unprimeable number, because it can be changed into a prime (21443311) 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 7 ways as a sum of consecutive naturals, for example, 96481 + ... + 96702.

It is an arithmetic number, because the mean of its divisors is an integer number (3670496).

Almost surely, 2^21443313 is an apocalyptic number.

It is an amenable number.

21443313 is a deficient number, since it is larger than the sum of its proper divisors (7920655).

21443313 is a wasteful number, since it uses less digits than its factorization.

21443313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193223.

The product of its digits is 864, while the sum is 21.

The square root of 21443313 is about 4630.6924968087. The cubic root of 21443313 is about 277.8202908384.

Adding to 21443313 its reverse (31334412), we get a palindrome (52777725).

The spelling of 21443313 in words is "twenty-one million, four hundred forty-three thousand, three hundred thirteen".