642717 has 6 divisors (see below), whose sum is σ = 928382. Its totient is φ = 428472.

The previous prime is 642701. The next prime is 642737. The reversal of 642717 is 717246.

642717 is a `hidden beast` number, since 642 + 7 + 17 = 666.

It can be written as a sum of positive squares in only one way, i.e., 549081 + 93636 = 741^2 + 306^2 .

It is not a de Polignac number, because 642717 - 2⁴ = 642701 is a prime.

It is a Duffinian number.

642717 is a lucky number.

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 642717.

It is not an unprimeable number, because it can be changed into a prime (642737) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35698 + ... + 35715.

2⁶⁴²⁷¹⁷ is an apocalyptic number.

It is an amenable number.

642717 is a deficient number, since it is larger than the sum of its proper divisors (285665).

642717 is a wasteful number, since it uses less digits than its factorization.

642717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71419 (or 71416 counting only the distinct ones).

The product of its digits is 2352, while the sum is 27.

The square root of 642717 is about 801.6963265477. The cubic root of 642717 is about 86.2991654155.

Subtracting 642717 from its reverse (717246), we obtain a square (74529 = 273²).

The spelling of 642717 in words is "six hundred forty-two thousand, seven hundred seventeen".