21142366 has 16 divisors (see below), whose sum is σ = 36347904. Its totient is φ = 9035064.

The previous prime is 21142361. The next prime is 21142379. The reversal of 21142366 is 66324112.

It is a self number, because there is not a number n which added to its sum of digits gives 21142366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3391 + ... + 7333.

It is an arithmetic number, because the mean of its divisors is an integer number (2271744).

Almost surely, 2^21142366 is an apocalyptic number.

21142366 is a deficient number, since it is larger than the sum of its proper divisors (15205538).

21142366 is a wasteful number, since it uses less digits than its factorization.

21142366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4335.

The product of its digits is 1728, while the sum is 25.

The square root of 21142366 is about 4598.0828613673. The cubic root of 21142366 is about 276.5144696039.

Adding to 21142366 its reverse (66324112), we get a palindrome (87466478).

The spelling of 21142366 in words is "twenty-one million, one hundred forty-two thousand, three hundred sixty-six".