21042202 has 4 divisors (see below), whose sum is σ = 31563306. Its totient is φ = 10521100.

The previous prime is 21042193. The next prime is 21042223. The reversal of 21042202 is 20224012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15848361 + 5193841 = 3981^2 + 2279^2 .

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5260549 + ... + 5260552.

Almost surely, 2^21042202 is an apocalyptic number.

21042202 is a deficient number, since it is larger than the sum of its proper divisors (10521104).

21042202 is a wasteful number, since it uses less digits than its factorization.

21042202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10521103.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 21042202 is about 4587.1779995984. The cubic root of 21042202 is about 276.0771068608.

Adding to 21042202 its reverse (20224012), we get a palindrome (41266214).

The spelling of 21042202 in words is "twenty-one million, forty-two thousand, two hundred two".