667642 has 4 divisors (see below), whose sum is σ = 1001466. Its totient is φ = 333820.

The previous prime is 667631. The next prime is 667643. The reversal of 667642 is 246766.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 638401 + 29241 = 799^2 + 171^2 .

It is not an unprimeable number, because it can be changed into a prime (667643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166909 + ... + 166912.

2⁶⁶⁷⁶⁴² is an apocalyptic number.

667642 is a deficient number, since it is larger than the sum of its proper divisors (333824).

667642 is a wasteful number, since it uses less digits than its factorization.

667642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333823.

The product of its digits is 12096, while the sum is 31.

The square root of 667642 is about 817.0936298858. The cubic root of 667642 is about 87.4006273224.

It can be divided in two parts, 66764 and 2, that added together give a palindrome (66766).

The spelling of 667642 in words is "six hundred sixty-seven thousand, six hundred forty-two".