21244003 has 4 divisors (see below), whose sum is σ = 23175288. Its totient is φ = 19312720.

The previous prime is 21244001. The next prime is 21244061. The reversal of 21244003 is 30044212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21244003 - 2¹ = 21244001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21244001) 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, 965626 + ... + 965647.

It is an arithmetic number, because the mean of its divisors is an integer number (5793822).

Almost surely, 2^21244003 is an apocalyptic number.

21244003 is a deficient number, since it is larger than the sum of its proper divisors (1931285).

21244003 is a wasteful number, since it uses less digits than its factorization.

21244003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1931284.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21244003 is about 4609.1217167699. The cubic root of 21244003 is about 276.9568544407.

Adding to 21244003 its reverse (30044212), we get a palindrome (51288215).

The spelling of 21244003 in words is "twenty-one million, two hundred forty-four thousand, three".