21144403 has 8 divisors (see below), whose sum is σ = 24621408. Its totient is φ = 17781504.

The previous prime is 21144373. The next prime is 21144419. The reversal of 21144403 is 30444112.

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 21144403 - 2¹³ = 21136211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21144203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28126 + ... + 28867.

It is an arithmetic number, because the mean of its divisors is an integer number (3077676).

Almost surely, 2^21144403 is an apocalyptic number.

21144403 is a deficient number, since it is larger than the sum of its proper divisors (3477005).

21144403 is an equidigital number, since it uses as much as digits as its factorization.

21144403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57053.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21144403 is about 4598.3043613924. The cubic root of 21144403 is about 276.5233497498.

Adding to 21144403 its reverse (30444112), we get a palindrome (51588515).

The spelling of 21144403 in words is "twenty-one million, one hundred forty-four thousand, four hundred three".