20680 has 32 divisors (see below), whose sum is σ = 51840. Its totient is φ = 7360.

The previous prime is 20663. The next prime is 20681. The reversal of 20680 is 8602.

It is a nialpdrome in base 12 and base 14.

It is not an unprimeable number, because it can be changed into a prime (20681) 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 in 7 ways as a sum of consecutive naturals, for example, 417 + ... + 463.

It is an arithmetic number, because the mean of its divisors is an integer number (1620).

2²⁰⁶⁸⁰ is an apocalyptic number.

20680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25920).

20680 is an abundant number, since it is smaller than the sum of its proper divisors (31160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20680 is a wasteful number, since it uses less digits than its factorization.

20680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 20680 is about 143.8054240980. The cubic root of 20680 is about 27.4483880438.

The spelling of 20680 in words is "twenty thousand, six hundred eighty".