21012204403 has 4 divisors (see below), whose sum is σ = 21015376960. Its totient is φ = 21009031848.

The previous prime is 21012204383. The next prime is 21012204427. The reversal of 21012204403 is 30440221012.

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

It is a cyclic number.

It is not a de Polignac number, because 21012204403 - 2⁵ = 21012204371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21019204403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1576323 + ... + 1589596.

It is an arithmetic number, because the mean of its divisors is an integer number (5253844240).

Almost surely, 2^21012204403 is an apocalyptic number.

21012204403 is a deficient number, since it is larger than the sum of its proper divisors (3172557).

21012204403 is an equidigital number, since it uses as much as digits as its factorization.

21012204403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3172556.

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

Adding to 21012204403 its reverse (30440221012), we get a palindrome (51452425415).

The spelling of 21012204403 in words is "twenty-one billion, twelve million, two hundred four thousand, four hundred three".