642768 has 40 divisors (see below), whose sum is σ = 1898688. Its totient is φ = 183552.

The previous prime is 642739. The next prime is 642769. The reversal of 642768 is 867246.

642768 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642769) by changing a digit.

642768 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 7 ways as a sum of consecutive naturals, for example, 621 + ... + 1292.

2⁶⁴²⁷⁶⁸ is an apocalyptic number.

It is an amenable number.

642768 is an abundant number, since it is smaller than the sum of its proper divisors (1255920).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642768 is a wasteful number, since it uses less digits than its factorization.

642768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1931 (or 1925 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 642768 is about 801.7281334717. The cubic root of 642768 is about 86.3014479862.

Subtracting from 642768 its product of digits (16128), we obtain a triangular number (626640 = T₁₁₁₉).

The spelling of 642768 in words is "six hundred forty-two thousand, seven hundred sixty-eight".