21002205051 has 6 divisors (see below), whose sum is σ = 30336518420. Its totient is φ = 14001470028.

The previous prime is 21002205013. The next prime is 21002205053. The reversal of 21002205051 is 15050220012.

It is not a de Polignac number, because 21002205051 - 2⁶ = 21002204987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002205053) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1166789161 + ... + 1166789178.

Almost surely, 2^21002205051 is an apocalyptic number.

21002205051 is a deficient number, since it is larger than the sum of its proper divisors (9334313369).

21002205051 is a wasteful number, since it uses less digits than its factorization.

21002205051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333578345 (or 2333578342 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

Adding to 21002205051 its reverse (15050220012), we get a palindrome (36052425063).

The spelling of 21002205051 in words is "twenty-one billion, two million, two hundred five thousand, fifty-one".