21440003 has 8 divisors (see below), whose sum is σ = 23834496. Its totient is φ = 19152000.

The previous prime is 21439997. The next prime is 21440017. The reversal of 21440003 is 30004412.

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

It is a cyclic number.

It is not a de Polignac number, because 21440003 - 2⁴ = 21439987 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 21440003.

It is not an unprimeable number, because it can be changed into a prime (21440203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26198 + ... + 27003.

It is an arithmetic number, because the mean of its divisors is an integer number (2979312).

Almost surely, 2^21440003 is an apocalyptic number.

21440003 is a deficient number, since it is larger than the sum of its proper divisors (2394493).

21440003 is a wasteful number, since it uses less digits than its factorization.

21440003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53245.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21440003 is about 4630.3350850667. The cubic root of 21440003 is about 277.8059952787.

Adding to 21440003 its reverse (30004412), we get a palindrome (51444415).

The spelling of 21440003 in words is "twenty-one million, four hundred forty thousand, three".