666142 has 4 divisors (see below), whose sum is σ = 999216. Its totient is φ = 333070.

The previous prime is 666139. The next prime is 666143. The reversal of 666142 is 241666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 241666 = 2 ⋅120833.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166534 + ... + 166537.

It is an arithmetic number, because the mean of its divisors is an integer number (249804).

2⁶⁶⁶¹⁴² is an apocalyptic number.

666142 is a deficient number, since it is larger than the sum of its proper divisors (333074).

666142 is a wasteful number, since it uses less digits than its factorization.

666142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333073.

The product of its digits is 1728, while the sum is 25.

The square root of 666142 is about 816.1752262842. The cubic root of 666142 is about 87.3351235316.

It can be divided in two parts, 666 and 142, that added together give a palindrome (808).

The spelling of 666142 in words is "six hundred sixty-six thousand, one hundred forty-two".