21203122003 has 4 divisors (see below), whose sum is σ = 24232139440. Its totient is φ = 18174104568.

The previous prime is 21203121967. The next prime is 21203122009. The reversal of 21203122003 is 30022130212.

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 21203122003 - 2¹⁷ = 21202990931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203122009) 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, 1514508708 + ... + 1514508721.

It is an arithmetic number, because the mean of its divisors is an integer number (6058034860).

Almost surely, 2^21203122003 is an apocalyptic number.

21203122003 is a deficient number, since it is larger than the sum of its proper divisors (3029017437).

21203122003 is an equidigital number, since it uses as much as digits as its factorization.

21203122003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3029017436.

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21203122003 its reverse (30022130212), we get a palindrome (51225252215).

The spelling of 21203122003 in words is "twenty-one billion, two hundred three million, one hundred twenty-two thousand, three".