20565766 has 8 divisors (see below), whose sum is σ = 33221664. Its totient is φ = 9491880.

The previous prime is 20565761. The next prime is 20565773. The reversal of 20565766 is 66756502.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20565761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 395470 + ... + 395521.

It is an arithmetic number, because the mean of its divisors is an integer number (4152708).

Almost surely, 2^20565766 is an apocalyptic number.

20565766 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20565766 is a deficient number, since it is larger than the sum of its proper divisors (12655898).

20565766 is a wasteful number, since it uses less digits than its factorization.

20565766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 791006.

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 20565766 is about 4534.9493933229. The cubic root of 20565766 is about 273.9775409158.

The spelling of 20565766 in words is "twenty million, five hundred sixty-five thousand, seven hundred sixty-six".