21112003 has 4 divisors (see below), whose sum is σ = 23031288. Its totient is φ = 19192720.

The previous prime is 21111991. The next prime is 21112009. The reversal of 21112003 is 30021112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112009) 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, 959626 + ... + 959647.

It is an arithmetic number, because the mean of its divisors is an integer number (5757822).

Almost surely, 2^21112003 is an apocalyptic number.

21112003 is a deficient number, since it is larger than the sum of its proper divisors (1919285).

21112003 is a wasteful number, since it uses less digits than its factorization.

21112003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919284.

The product of its (nonzero) digits is 12, while the sum is 10.

The square root of 21112003 is about 4594.7799729693. The cubic root of 21112003 is about 276.3820367566.

Adding to 21112003 its reverse (30021112), we get a palindrome (51133115).

It can be divided in two parts, 2111 and 2003, that added together give a palindrome (4114).

The spelling of 21112003 in words is "twenty-one million, one hundred twelve thousand, three".