20788 has 6 divisors (see below), whose sum is σ = 36386. Its totient is φ = 10392.

The previous prime is 20773. The next prime is 20789. The reversal of 20788 is 88702.

It can be written as a sum of positive squares in only one way, i.e., 17424 + 3364 = 132^2 + 58^2 .

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20789) by changing a digit.

20788 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2595 + ... + 2602.

2²⁰⁷⁸⁸ is an apocalyptic number.

It is an amenable number.

20788 is a deficient number, since it is larger than the sum of its proper divisors (15598).

20788 is a wasteful number, since it uses less digits than its factorization.

20788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5201 (or 5199 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 25.

The square root of 20788 is about 144.1804425017. The cubic root of 20788 is about 27.4960875977.

It can be divided in two parts, 20 and 788, that added together give a palindrome (808).

The spelling of 20788 in words is "twenty thousand, seven hundred eighty-eight".