20775 has 12 divisors (see below), whose sum is σ = 34472. Its totient is φ = 11040.

The previous prime is 20773. The next prime is 20789. The reversal of 20775 is 57702.

It is not a de Polignac number, because 20775 - 2¹ = 20773 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11 and base 14.

It is a zygodrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 64 + ... + 213.

2²⁰⁷⁷⁵ is an apocalyptic number.

20775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20775 is a deficient number, since it is larger than the sum of its proper divisors (13697).

20775 is a wasteful number, since it uses less digits than its factorization.

20775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 490, while the sum is 21.

The square root of 20775 is about 144.1353530540. The cubic root of 20775 is about 27.4903547442.

It can be divided in two parts, 207 and 75, that added together give a palindrome (282).

The spelling of 20775 in words is "twenty thousand, seven hundred seventy-five".