21168008 has 8 divisors (see below), whose sum is σ = 39690030. Its totient is φ = 10584000.

The previous prime is 21167989. The next prime is 21168023. The reversal of 21168008 is 80086112.

It can be written as a sum of positive squares in only one way, i.e., 20593444 + 574564 = 4538^2 + 758^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1322993 + ... + 1323008.

Almost surely, 2^21168008 is an apocalyptic number.

It is an amenable number.

21168008 is a deficient number, since it is larger than the sum of its proper divisors (18522022).

21168008 is a wasteful number, since it uses less digits than its factorization.

21168008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2646007 (or 2646003 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 21168008 is about 4600.8703524442. The cubic root of 21168008 is about 276.6262123718.

The spelling of 21168008 in words is "twenty-one million, one hundred sixty-eight thousand, eight".