668042 has 4 divisors (see below), whose sum is σ = 1002066. Its totient is φ = 334020.

The previous prime is 668033. The next prime is 668047. The reversal of 668042 is 240866.

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., 609961 + 58081 = 781^2 + 241^2 .

It is a super-2 number, since 2×668042² = 892560227528, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (668047) by changing a digit.

668042 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 as a sum of consecutive naturals, namely, 167009 + ... + 167012.

2⁶⁶⁸⁰⁴² is an apocalyptic number.

668042 is a deficient number, since it is larger than the sum of its proper divisors (334024).

668042 is a wasteful number, since it uses less digits than its factorization.

668042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334023.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 668042 is about 817.3383632254. The cubic root of 668042 is about 87.4180784272.

The spelling of 668042 in words is "six hundred sixty-eight thousand, forty-two".