21168704 has 28 divisors (see below), whose sum is σ = 42170604. Its totient is φ = 10543104.

The previous prime is 21168703. The next prime is 21168709. The reversal of 21168704 is 40786112.

It can be written as a sum of positive squares in 2 ways, for example, as 4194304 + 16974400 = 2048^2 + 4120^2 .

It is a super-2 number, since 2×21168704² = 896228058079232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21168701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22124 + ... + 23060.

It is an arithmetic number, because the mean of its divisors is an integer number (1506093).

Almost surely, 2^21168704 is an apocalyptic number.

It is an amenable number.

21168704 is a deficient number, since it is larger than the sum of its proper divisors (21001900).

21168704 is an equidigital number, since it uses as much as digits as its factorization.

21168704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1302 (or 1292 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21168704 is about 4600.9459896852. The cubic root of 21168704 is about 276.6292441440.

The spelling of 21168704 in words is "twenty-one million, one hundred sixty-eight thousand, seven hundred four".