21202042 has 8 divisors (see below), whose sum is σ = 31922100. Its totient is φ = 10561344.

The previous prime is 21202039. The next prime is 21202079. The reversal of 21202042 is 24020212.

It can be written as a sum of positive squares in 2 ways, for example, as 19989841 + 1212201 = 4471^2 + 1101^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19167 + ... + 20242.

Almost surely, 2^21202042 is an apocalyptic number.

21202042 is a deficient number, since it is larger than the sum of its proper divisors (10720058).

21202042 is a wasteful number, since it uses less digits than its factorization.

21202042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39680.

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

The square root of 21202042 is about 4604.5675149790. The cubic root of 21202042 is about 276.7743865309.

Adding to 21202042 its reverse (24020212), we get a palindrome (45222254).

The spelling of 21202042 in words is "twenty-one million, two hundred two thousand, forty-two".