21068288 has 20 divisors (see below), whose sum is σ = 42096450. Its totient is φ = 10533888.

The previous prime is 21068263. The next prime is 21068291. The reversal of 21068288 is 88286012.

It can be written as a sum of positive squares in only one way, i.e., 20502784 + 565504 = 4528^2 + 752^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20063 + ... + 21086.

Almost surely, 2^21068288 is an apocalyptic number.

It is an amenable number.

21068288 is a deficient number, since it is larger than the sum of its proper divisors (21028162).

21068288 is an frugal number, since it uses more digits than its factorization.

21068288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41167 (or 41151 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 21068288 is about 4590.0204792571. The cubic root of 21068288 is about 276.1911439351.

The spelling of 21068288 in words is "twenty-one million, sixty-eight thousand, two hundred eighty-eight".