20797 has 4 divisors (see below), whose sum is σ = 23776. Its totient is φ = 17820.

The previous prime is 20789. The next prime is 20807. The reversal of 20797 is 79702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20797 - 2³ = 20789 is a prime.

It is a Duffinian number.

20797 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20707) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1479 + ... + 1492.

It is an arithmetic number, because the mean of its divisors is an integer number (5944).

2²⁰⁷⁹⁷ is an apocalyptic number.

It is an amenable number.

20797 is a deficient number, since it is larger than the sum of its proper divisors (2979).

20797 is an equidigital number, since it uses as much as digits as its factorization.

20797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2978.

The product of its (nonzero) digits is 882, while the sum is 25.

The square root of 20797 is about 144.2116500148. The cubic root of 20797 is about 27.5000550963.

The spelling of 20797 in words is "twenty thousand, seven hundred ninety-seven".