21033121003 has 4 divisors (see below), whose sum is σ = 21249957400. Its totient is φ = 20816284608.

The previous prime is 21033120971. The next prime is 21033121019. The reversal of 21033121003 is 30012133012.

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 21033121003 - 2⁵ = 21033120971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21033121033) 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, 108418053 + ... + 108418246.

It is an arithmetic number, because the mean of its divisors is an integer number (5312489350).

Almost surely, 2^21033121003 is an apocalyptic number.

21033121003 is a deficient number, since it is larger than the sum of its proper divisors (216836397).

21033121003 is an equidigital number, since it uses as much as digits as its factorization.

21033121003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216836396.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21033121003 its reverse (30012133012), we get a palindrome (51045254015).

The spelling of 21033121003 in words is "twenty-one billion, thirty-three million, one hundred twenty-one thousand, three".