642718 has 4 divisors (see below), whose sum is σ = 964080. Its totient is φ = 321358.

The previous prime is 642701. The next prime is 642737. The reversal of 642718 is 817246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 817246 = 2 ⋅408623.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160678 + ... + 160681.

It is an arithmetic number, because the mean of its divisors is an integer number (241020).

2⁶⁴²⁷¹⁸ is an apocalyptic number.

642718 is a deficient number, since it is larger than the sum of its proper divisors (321362).

642718 is a wasteful number, since it uses less digits than its factorization.

642718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321361.

The product of its digits is 2688, while the sum is 28.

The square root of 642718 is about 801.6969502250. The cubic root of 642718 is about 86.2992101729.

It can be divided in two parts, 6 and 42718, that added together give a palindrome (42724).

The spelling of 642718 in words is "six hundred forty-two thousand, seven hundred eighteen".