21251002203 has 12 divisors (see below), whose sum is σ = 30697795128. Its totient is φ = 14166456480.

The previous prime is 21251002147. The next prime is 21251002217. The reversal of 21251002203 is 30220015212.

It is not a de Polignac number, because 21251002203 - 2³⁴ = 4071133019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21251002103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 102148 + ... + 230078.

It is an arithmetic number, because the mean of its divisors is an integer number (2558149594).

Almost surely, 2^21251002203 is an apocalyptic number.

21251002203 is a deficient number, since it is larger than the sum of its proper divisors (9446792925).

21251002203 is a wasteful number, since it uses less digits than its factorization.

21251002203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146394 (or 146391 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

Adding to 21251002203 its reverse (30220015212), we get a palindrome (51471017415).

The spelling of 21251002203 in words is "twenty-one billion, two hundred fifty-one million, two thousand, two hundred three".