21000202 has 16 divisors (see below), whose sum is σ = 33814152. Its totient is φ = 9745920.

The previous prime is 21000193. The next prime is 21000229. The reversal of 21000202 is 20200012.

It is a happy number.

21000202 is an esthetic number in base 9, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 4 ways, for example, as 20985561 + 14641 = 4581^2 + 121^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1749 + ... + 6712.

Almost surely, 2^21000202 is an apocalyptic number.

21000202 is a deficient number, since it is larger than the sum of its proper divisors (12813950).

21000202 is a wasteful number, since it uses less digits than its factorization.

21000202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8553.

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 21000202 is about 4582.5977349098. The cubic root of 21000202 is about 275.8933022427.

Adding to 21000202 its reverse (20200012), we get a palindrome (41200214).

The spelling of 21000202 in words is "twenty-one million, two hundred two", and thus it is an aban number.