21002242 has 16 divisors (see below), whose sum is σ = 33446520. Its totient is φ = 9856768.

The previous prime is 21002231. The next prime is 21002251. The reversal of 21002242 is 24220012.

It can be written as a sum of positive squares in 4 ways, for example, as 9853321 + 11148921 = 3139^2 + 3339^2 .

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, 18384 + ... + 19492.

Almost surely, 2^21002242 is an apocalyptic number.

21002242 is a deficient number, since it is larger than the sum of its proper divisors (12444278).

21002242 is a wasteful number, since it uses less digits than its factorization.

21002242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1685.

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

The square root of 21002242 is about 4582.8203106821. The cubic root of 21002242 is about 275.9022355554.

Adding to 21002242 its reverse (24220012), we get a palindrome (45222254).

The spelling of 21002242 in words is "twenty-one million, two thousand, two hundred forty-two".