66642 has 16 divisors (see below), whose sum is σ = 138240. Its totient is φ = 21392.

The previous prime is 66629. The next prime is 66643. The reversal of 66642 is 24666.

It is a plaindrome in base 9 and base 13.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66643) by changing a digit.

66642 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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, 18 + ... + 365.

It is an arithmetic number, because the mean of its divisors is an integer number (8640).

2⁶⁶⁶⁴² is an apocalyptic number.

66642 is an abundant number, since it is smaller than the sum of its proper divisors (71598).

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 (69120).

66642 is a wasteful number, since it uses less digits than its factorization.

66642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417.

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

The square root of 66642 is about 258.1511185333. The cubic root of 66642 is about 40.5430117653.

Adding to 66642 its sum of digits (24), we get a palindrome (66666).

It can be divided in two parts, 6664 and 2, that added together give a palindrome (6666).

The spelling of 66642 in words is "sixty-six thousand, six hundred forty-two".