21427066 has 8 divisors (see below), whose sum is σ = 32164020. Its totient is φ = 10705728.

The previous prime is 21427039. The next prime is 21427073. The reversal of 21427066 is 66072412.

It can be written as a sum of positive squares in 2 ways, for example, as 19936225 + 1490841 = 4465^2 + 1221^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 540 + ... + 6568.

Almost surely, 2^21427066 is an apocalyptic number.

21427066 is a deficient number, since it is larger than the sum of its proper divisors (10736954).

21427066 is a wasteful number, since it uses less digits than its factorization.

21427066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7808.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 21427066 is about 4628.9378911366. The cubic root of 21427066 is about 277.7501075490.

Adding to 21427066 its reverse (66072412), we get a palindrome (87499478).

The spelling of 21427066 in words is "twenty-one million, four hundred twenty-seven thousand, sixty-six".