642117 has 8 divisors (see below), whose sum is σ = 978496. Its totient is φ = 366912.

The previous prime is 642113. The next prime is 642121. The reversal of 642117 is 711246.

It is an interprime number because it is at equal distance from previous prime (642113) and next prime (642121).

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

It is not a de Polignac number, because 642117 - 2² = 642113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 30577 = 642117 / (6 + 4 + 2 + 1 + 1 + 7).

It is a Duffinian number.

642117 is a lucky number.

It is a zygodrome in base 9.

It is a junction number, because it is equal to n+sod(n) for n = 642093 and 642102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15268 + ... + 15309.

It is an arithmetic number, because the mean of its divisors is an integer number (122312).

2⁶⁴²¹¹⁷ is an apocalyptic number.

It is an amenable number.

642117 is a deficient number, since it is larger than the sum of its proper divisors (336379).

642117 is a wasteful number, since it uses less digits than its factorization.

642117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30587.

The product of its digits is 336, while the sum is 21.

The square root of 642117 is about 801.3220326436. The cubic root of 642117 is about 86.2723025711.

The spelling of 642117 in words is "six hundred forty-two thousand, one hundred seventeen".