21427268 has 6 divisors (see below), whose sum is σ = 37497726. Its totient is φ = 10713632.

The previous prime is 21427247. The next prime is 21427271. The reversal of 21427268 is 86272412.

It can be written as a sum of positive squares in only one way, i.e., 19909444 + 1517824 = 4462^2 + 1232^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2678405 + ... + 2678412.

It is an arithmetic number, because the mean of its divisors is an integer number (6249621).

Almost surely, 2^21427268 is an apocalyptic number.

It is an amenable number.

21427268 is a deficient number, since it is larger than the sum of its proper divisors (16070458).

21427268 is a wasteful number, since it uses less digits than its factorization.

21427268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5356821 (or 5356819 counting only the distinct ones).

The product of its digits is 10752, while the sum is 32.

The square root of 21427268 is about 4628.9597103453. The cubic root of 21427268 is about 277.7509803601.

The spelling of 21427268 in words is "twenty-one million, four hundred twenty-seven thousand, two hundred sixty-eight".