21444293 has 16 divisors (see below), whose sum is σ = 25744320. Its totient is φ = 17646336.

The previous prime is 21444289. The next prime is 21444299. The reversal of 21444293 is 39244412.

It is a cyclic number.

It is not a de Polignac number, because 21444293 - 2² = 21444289 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444299) 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 15 ways as a sum of consecutive naturals, for example, 1646 + ... + 6752.

It is an arithmetic number, because the mean of its divisors is an integer number (1609020).

Almost surely, 2^21444293 is an apocalyptic number.

It is an amenable number.

21444293 is a deficient number, since it is larger than the sum of its proper divisors (4300027).

21444293 is a wasteful number, since it uses less digits than its factorization.

21444293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5156.

The product of its digits is 6912, while the sum is 29.

The square root of 21444293 is about 4630.7983113066. The cubic root of 21444293 is about 277.8245230783.

The spelling of 21444293 in words is "twenty-one million, four hundred forty-four thousand, two hundred ninety-three".