21002203 has 2 divisors, whose sum is σ = 21002204. Its totient is φ = 21002202.

The previous prime is 21002129. The next prime is 21002207. The reversal of 21002203 is 30220012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21002203 - 2¹³ = 20994011 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21002203.

It is not a weakly prime, because it can be changed into another prime (21002207) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501101 + 10501102.

It is an arithmetic number, because the mean of its divisors is an integer number (10501102).

Almost surely, 2^21002203 is an apocalyptic number.

21002203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002203 is an equidigital number, since it uses as much as digits as its factorization.

21002203 is an evil number, because the sum of its binary digits is even.

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

The square root of 21002203 is about 4582.8160556584. The cubic root of 21002203 is about 275.9020647769.

Adding to 21002203 its reverse (30220012), we get a palindrome (51222215).

The spelling of 21002203 in words is "twenty-one million, two thousand, two hundred three".