21068210 has 16 divisors (see below), whose sum is σ = 39231000. Its totient is φ = 8136576.

The previous prime is 21068209. The next prime is 21068213. The reversal of 21068210 is 1286012.

It can be written as a sum of positive squares in 4 ways, for example, as 14922769 + 6145441 = 3863^2 + 2479^2 .

It is not an unprimeable number, because it can be changed into a prime (21068213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36035 + ... + 36614.

Almost surely, 2^21068210 is an apocalyptic number.

21068210 is a deficient number, since it is larger than the sum of its proper divisors (18162790).

21068210 is a wasteful number, since it uses less digits than its factorization.

21068210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72685.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 21068210 is about 4590.0119825552. The cubic root of 21068210 is about 276.1908030921.

The spelling of 21068210 in words is "twenty-one million, sixty-eight thousand, two hundred ten".