21221002203 has 16 divisors (see below), whose sum is σ = 28619085600. Its totient is φ = 13985199360.

The previous prime is 21221002193. The next prime is 21221002217. The reversal of 21221002203 is 30220012212.

It is a happy number.

It is not a de Polignac number, because 21221002203 - 2¹² = 21220998107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221002223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2029593 + ... + 2040021.

It is an arithmetic number, because the mean of its divisors is an integer number (1788692850).

Almost surely, 2^21221002203 is an apocalyptic number.

21221002203 is a deficient number, since it is larger than the sum of its proper divisors (7398083397).

21221002203 is a wasteful number, since it uses less digits than its factorization.

21221002203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18142.

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21221002203 its reverse (30220012212), we get a palindrome (51441014415).

The spelling of 21221002203 in words is "twenty-one billion, two hundred twenty-one million, two thousand, two hundred three".