642568 has 16 divisors (see below), whose sum is σ = 1244160. Its totient is φ = 310800.

The previous prime is 642563. The next prime is 642581. The reversal of 642568 is 865246.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (642563) by changing a digit.

642568 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1048 + ... + 1543.

It is an arithmetic number, because the mean of its divisors is an integer number (77760).

2⁶⁴²⁵⁶⁸ is an apocalyptic number.

It is an amenable number.

642568 is a deficient number, since it is larger than the sum of its proper divisors (601592).

642568 is a wasteful number, since it uses less digits than its factorization.

642568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2628 (or 2624 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 642568 is about 801.6033932064. The cubic root of 642568 is about 86.2924960367.

The spelling of 642568 in words is "six hundred forty-two thousand, five hundred sixty-eight".