642017 has 4 divisors (see below), whose sum is σ = 645120. Its totient is φ = 638916.

The previous prime is 642013. The next prime is 642049. The reversal of 642017 is 710246.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 642017 - 2² = 642013 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 642017.

It is not an unprimeable number, because it can be changed into a prime (642011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1217 + ... + 1662.

It is an arithmetic number, because the mean of its divisors is an integer number (161280).

2⁶⁴²⁰¹⁷ is an apocalyptic number.

It is an amenable number.

642017 is a deficient number, since it is larger than the sum of its proper divisors (3103).

642017 is a wasteful number, since it uses less digits than its factorization.

642017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3102.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 642017 is about 801.2596333274. The cubic root of 642017 is about 86.2678238036.

The spelling of 642017 in words is "six hundred forty-two thousand, seventeen".