21001211003 has 4 divisors (see below), whose sum is σ = 21004083048. Its totient is φ = 20998338960.

The previous prime is 21001210991. The next prime is 21001211027. The reversal of 21001211003 is 30011210012.

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 21001211003 - 2²⁰ = 21000162427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001211093) 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, 1425026 + ... + 1439687.

It is an arithmetic number, because the mean of its divisors is an integer number (5251020762).

Almost surely, 2^21001211003 is an apocalyptic number.

21001211003 is a deficient number, since it is larger than the sum of its proper divisors (2872045).

21001211003 is an equidigital number, since it uses as much as digits as its factorization.

21001211003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2872044.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21001211003 its reverse (30011210012), we get a palindrome (51012421015).

Subtracting 21001211003 from its reverse (30011210012), we obtain a palindrome (9009999009).

The spelling of 21001211003 in words is "twenty-one billion, one million, two hundred eleven thousand, three".