21001044003 has 16 divisors (see below), whose sum is σ = 28333324800. Its totient is φ = 13835625440.

The previous prime is 21001043983. The next prime is 21001044007. The reversal of 21001044003 is 30044010012.

It is a cyclic number.

It is not a de Polignac number, because 21001044003 - 2²⁰ = 20999995427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21001044007) 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, 17868 + ... + 205721.

It is an arithmetic number, because the mean of its divisors is an integer number (1770832800).

Almost surely, 2^21001044003 is an apocalyptic number.

21001044003 is a deficient number, since it is larger than the sum of its proper divisors (7332280797).

21001044003 is a wasteful number, since it uses less digits than its factorization.

21001044003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223962.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21001044003 its reverse (30044010012), we get a palindrome (51045054015).

The spelling of 21001044003 in words is "twenty-one billion, one million, forty-four thousand, three".