21190201 has 6 divisors (see below), whose sum is σ = 21364910. Its totient is φ = 21016896.

The previous prime is 21190189. The next prime is 21190207. The reversal of 21190201 is 10209112.

It can be written as a sum of positive squares in 3 ways, for example, as 1155625 + 20034576 = 1075^2 + 4476^2 .

It is not a de Polignac number, because 21190201 - 2⁹ = 21189689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21190207) 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, 18205 + ... + 19333.

Almost surely, 2^21190201 is an apocalyptic number.

It is an amenable number.

21190201 is a deficient number, since it is larger than the sum of its proper divisors (174709).

21190201 is an equidigital number, since it uses as much as digits as its factorization.

21190201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1403 (or 1266 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 21190201 is about 4603.2815468967. The cubic root of 21190201 is about 276.7228522525.

Adding to 21190201 its reverse (10209112), we get a palindrome (31399313).

The spelling of 21190201 in words is "twenty-one million, one hundred ninety thousand, two hundred one".