20670 has 32 divisors (see below), whose sum is σ = 54432. Its totient is φ = 4992.

The previous prime is 20663. The next prime is 20681. The reversal of 20670 is 7602.

20670 is digitally balanced in base 4 and base 6, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an Ulam number.

20670 is strictly pandigital in base 6.

It is a Curzon number.

It is a nialpdrome in base 12, base 13 and base 14.

It is a zygodrome in base 12 and base 14.

It is a congruent number.

It is an unprimeable number.

20670 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 in 15 ways as a sum of consecutive naturals, for example, 364 + ... + 416.

It is an arithmetic number, because the mean of its divisors is an integer number (1701).

2²⁰⁶⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20670, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27216).

20670 is an abundant number, since it is smaller than the sum of its proper divisors (33762).

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

20670 is a wasteful number, since it uses less digits than its factorization.

20670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76.

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 20670 is about 143.7706506906. The cubic root of 20670 is about 27.4439630255.

20670 divided by its sum of digits (15) gives a triangular number (1378 = T₅₂).

It can be divided in two parts, 206 and 70, that added together give a triangular number (276 = T₂₃).

The spelling of 20670 in words is "twenty thousand, six hundred seventy".