21144008 has 16 divisors (see below), whose sum is σ = 39720780. Its totient is φ = 10551808.

The previous prime is 21143999. The next prime is 21144029. The reversal of 21144008 is 80044112.

It can be written as a sum of positive squares in 2 ways, for example, as 20593444 + 550564 = 4538^2 + 742^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2516 + ... + 6972.

Almost surely, 2^21144008 is an apocalyptic number.

It is an amenable number.

21144008 is a deficient number, since it is larger than the sum of its proper divisors (18576772).

21144008 is a wasteful number, since it uses less digits than its factorization.

21144008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5056 (or 5052 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 21144008 is about 4598.2614105768. The cubic root of 21144008 is about 276.5216278221.

The spelling of 21144008 in words is "twenty-one million, one hundred forty-four thousand, eight".