21201044403 has 96 divisors (see below), whose sum is σ = 37808805888. Its totient is φ = 10307911680.

The previous prime is 21201044401. The next prime is 21201044479. The reversal of 21201044403 is 30444010212.

It is not a de Polignac number, because 21201044403 - 2¹ = 21201044401 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21201044403.

It is not an unprimeable number, because it can be changed into a prime (21201044401) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8335750 + ... + 8338292.

It is an arithmetic number, because the mean of its divisors is an integer number (393841728).

Almost surely, 2^21201044403 is an apocalyptic number.

21201044403 is a deficient number, since it is larger than the sum of its proper divisors (16607761485).

21201044403 is a wasteful number, since it uses less digits than its factorization.

21201044403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2785 (or 2774 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21201044403 its reverse (30444010212), we get a palindrome (51645054615).

The spelling of 21201044403 in words is "twenty-one billion, two hundred one million, forty-four thousand, four hundred three".