20904566 has 8 divisors (see below), whose sum is σ = 32024160. Its totient is φ = 10229848.

The previous prime is 20904511. The next prime is 20904589. The reversal of 20904566 is 66540902.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111101 + ... + 111288.

It is an arithmetic number, because the mean of its divisors is an integer number (4003020).

Almost surely, 2^20904566 is an apocalyptic number.

20904566 is a deficient number, since it is larger than the sum of its proper divisors (11119594).

20904566 is a wasteful number, since it uses less digits than its factorization.

20904566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222438.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 20904566 is about 4572.1511348598. The cubic root of 20904566 is about 275.4738541046.

The spelling of 20904566 in words is "twenty million, nine hundred four thousand, five hundred sixty-six".