21210203 has 16 divisors (see below), whose sum is σ = 25873344. Its totient is φ = 16972800.

The previous prime is 21210197. The next prime is 21210221. The reversal of 21210203 is 30201212.

It is a happy number.

It is not a de Polignac number, because 21210203 - 2¹⁴ = 21193819 is a prime.

It is a super-2 number, since 2×21210203² = 899745422602418, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21210283) 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, 15653 + ... + 16953.

It is an arithmetic number, because the mean of its divisors is an integer number (1617084).

Almost surely, 2^21210203 is an apocalyptic number.

21210203 is a deficient number, since it is larger than the sum of its proper divisors (4663141).

21210203 is a wasteful number, since it uses less digits than its factorization.

21210203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1462.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21210203 is about 4605.4536150091. The cubic root of 21210203 is about 276.8098935829.

Adding to 21210203 its reverse (30201212), we get a palindrome (51411415).

The spelling of 21210203 in words is "twenty-one million, two hundred ten thousand, two hundred three".