640142 has 8 divisors (see below), whose sum is σ = 964656. Its totient is φ = 318592.

The previous prime is 640139. The next prime is 640151. The reversal of 640142 is 241046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 640142.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640142.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83 + ... + 1134.

It is an arithmetic number, because the mean of its divisors is an integer number (120582).

2⁶⁴⁰¹⁴² is an apocalyptic number.

640142 is a deficient number, since it is larger than the sum of its proper divisors (324514).

640142 is a wasteful number, since it uses less digits than its factorization.

640142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1482.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 640142 is about 800.0887450777. The cubic root of 640142 is about 86.1837606659.

Adding to 640142 its reverse (241046), we get a palindrome (881188).

The spelling of 640142 in words is "six hundred forty thousand, one hundred forty-two".