21000022003 has 4 divisors (see below), whose sum is σ = 21007199520. Its totient is φ = 20992844488.

The previous prime is 21000021907. The next prime is 21000022007. The reversal of 21000022003 is 30022000012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21000022003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000022007) 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, 3584368 + ... + 3590221.

It is an arithmetic number, because the mean of its divisors is an integer number (5251799880).

Almost surely, 2^21000022003 is an apocalyptic number.

21000022003 is a deficient number, since it is larger than the sum of its proper divisors (7177517).

21000022003 is an equidigital number, since it uses as much as digits as its factorization.

21000022003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7177516.

The product of its (nonzero) digits is 24, while the sum is 10.

Adding to 21000022003 its reverse (30022000012), we get a palindrome (51022022015).

The spelling of 21000022003 in words is "twenty-one billion, twenty-two thousand, three".