42666 has 16 divisors (see below), whose sum is σ = 92064. Its totient is φ = 13104.

The previous prime is 42649. The next prime is 42667. The reversal of 42666 is 66624.

42666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

42666 is a modest number, since divided by 666 gives 42 as remainder.

It is a Curzon number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (42667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196 + ... + 351.

It is an arithmetic number, because the mean of its divisors is an integer number (5754).

2⁴²⁶⁶⁶ is an apocalyptic number.

42666 is an abundant number, since it is smaller than the sum of its proper divisors (49398).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46032).

42666 is a wasteful number, since it uses less digits than its factorization.

42666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565.

The product of its digits is 1728, while the sum is 24.

The square root of 42666 is about 206.5574980484. The cubic root of 42666 is about 34.9430365926.

It can be divided in two parts, 42 and 666, that multiplied together give a palindrome (27972).

The spelling of 42666 in words is "forty-two thousand, six hundred sixty-six".