20664285 has 16 divisors (see below), whose sum is σ = 33224640. Its totient is φ = 10967040.

The previous prime is 20664257. The next prime is 20664289. The reversal of 20664285 is 58246602.

It is not a de Polignac number, because 20664285 - 2¹⁷ = 20533213 is a prime.

It is a super-2 number, since 2×20664285² = 854025349122450, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20664289) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 100 + ... + 6429.

It is an arithmetic number, because the mean of its divisors is an integer number (2076540).

Almost surely, 2^20664285 is an apocalyptic number.

It is an amenable number.

20664285 is a deficient number, since it is larger than the sum of its proper divisors (12560355).

20664285 is a wasteful number, since it uses less digits than its factorization.

20664285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6748.

The product of its (nonzero) digits is 23040, while the sum is 33.

The square root of 20664285 is about 4545.7986097054. The cubic root of 20664285 is about 274.4143348667.

The spelling of 20664285 in words is "twenty million, six hundred sixty-four thousand, two hundred eighty-five".