20664835 has 4 divisors (see below), whose sum is σ = 24797808. Its totient is φ = 16531864.

The previous prime is 20664829. The next prime is 20664851. The reversal of 20664835 is 53846602.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20664835 - 2³ = 20664827 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20664835.

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 in 3 ways as a sum of consecutive naturals, for example, 2066479 + ... + 2066488.

It is an arithmetic number, because the mean of its divisors is an integer number (6199452).

Almost surely, 2^20664835 is an apocalyptic number.

20664835 is a deficient number, since it is larger than the sum of its proper divisors (4132973).

20664835 is an equidigital number, since it uses as much as digits as its factorization.

20664835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4132972.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 20664835 is about 4545.8591047238. The cubic root of 20664835 is about 274.4167694463.

The spelling of 20664835 in words is "twenty million, six hundred sixty-four thousand, eight hundred thirty-five".