642660 has 24 divisors (see below), whose sum is σ = 1799616. Its totient is φ = 171360.

The previous prime is 642623. The next prime is 642673. The reversal of 642660 is 66246.

642660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 642660.

It is a congruent number.

It is an unprimeable number.

642660 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, 5296 + ... + 5415.

It is an arithmetic number, because the mean of its divisors is an integer number (74984).

2⁶⁴²⁶⁶⁰ is an apocalyptic number.

642660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

642660 is an abundant number, since it is smaller than the sum of its proper divisors (1156956).

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

642660 is a wasteful number, since it uses less digits than its factorization.

642660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10723 (or 10721 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 642660 is about 801.6607761391. The cubic root of 642660 is about 86.2966141641.

The spelling of 642660 in words is "six hundred forty-two thousand, six hundred sixty".