20667 has 6 divisors (see below), whose sum is σ = 27892. Its totient is φ = 13612.

The previous prime is 20663. The next prime is 20681. The reversal of 20667 is 76602.

20667 is nontrivially palindromic in base 9.

20667 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 20667 - 2² = 20663 is a prime.

It is a Duffinian number.

20667 is an undulating number in base 9.

It is a plaindrome in base 11.

It is a nialpdrome in base 12 and base 14.

It is not an unprimeable number, because it can be changed into a prime (20663) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 208 + ... + 290.

2²⁰⁶⁶⁷ is an apocalyptic number.

20667 is a deficient number, since it is larger than the sum of its proper divisors (7225).

20667 is an frugal number, since it uses more digits than its factorization.

20667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 20667 is about 143.7602170282. The cubic root of 20667 is about 27.4426352418.

The spelling of 20667 in words is "twenty thousand, six hundred sixty-seven".