20704 has 12 divisors (see below), whose sum is σ = 40824. Its totient is φ = 10336.

The previous prime is 20693. The next prime is 20707. The reversal of 20704 is 40702.

It is a plaindrome in base 14.

It is a nialpdrome in base 12.

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 pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 292 + ... + 355.

It is an arithmetic number, because the mean of its divisors is an integer number (3402).

2²⁰⁷⁰⁴ is an apocalyptic number.

It is an amenable number.

20704 is a deficient number, since it is larger than the sum of its proper divisors (20120).

20704 is an equidigital number, since it uses as much as digits as its factorization.

20704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657 (or 649 counting only the distinct ones).

The product of its (nonzero) digits is 56, while the sum is 13.

The square root of 20704 is about 143.8888459888. Note that the first 4 decimals coincide. The cubic root of 20704 is about 27.4590022708.

The spelling of 20704 in words is "twenty thousand, seven hundred four", and thus it is an iban number.