20320665 has 8 divisors (see below), whose sum is σ = 32513088. Its totient is φ = 10837680.

The previous prime is 20320609. The next prime is 20320669. The reversal of 20320665 is 56602302.

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

It is not a de Polignac number, because 20320665 - 2⁷ = 20320537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20320669) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 677341 + ... + 677370.

It is an arithmetic number, because the mean of its divisors is an integer number (4064136).

Almost surely, 2^20320665 is an apocalyptic number.

It is an amenable number.

20320665 is a deficient number, since it is larger than the sum of its proper divisors (12192423).

20320665 is a wasteful number, since it uses less digits than its factorization.

20320665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1354719.

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 20320665 is about 4507.8448287402. The cubic root of 20320665 is about 272.8847747310.

Adding to 20320665 its reverse (56602302), we get a palindrome (76922967).

The spelling of 20320665 in words is "twenty million, three hundred twenty thousand, six hundred sixty-five".