21234566 has 16 divisors (see below), whose sum is σ = 34311168. Its totient is φ = 9827400.

The previous prime is 21234541. The next prime is 21234593. The reversal of 21234566 is 66543212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6020 + ... + 8871.

It is an arithmetic number, because the mean of its divisors is an integer number (2144448).

Almost surely, 2^21234566 is an apocalyptic number.

21234566 is a deficient number, since it is larger than the sum of its proper divisors (13076602).

21234566 is a wasteful number, since it uses less digits than its factorization.

21234566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14947.

The product of its digits is 8640, while the sum is 29.

The square root of 21234566 is about 4608.0978722245. The cubic root of 21234566 is about 276.9158384900.

Adding to 21234566 its reverse (66543212), we get a palindrome (87777778).

The spelling of 21234566 in words is "twenty-one million, two hundred thirty-four thousand, five hundred sixty-six".