642644 has 12 divisors (see below), whose sum is σ = 1130304. Its totient is φ = 319704.

The previous prime is 642623. The next prime is 642673. The reversal of 642644 is 446246.

642644 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1157 + ... + 1619.

It is an arithmetic number, because the mean of its divisors is an integer number (94192).

2⁶⁴²⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

642644 is a deficient number, since it is larger than the sum of its proper divisors (487660).

642644 is a wasteful number, since it uses less digits than its factorization.

642644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 814 (or 812 counting only the distinct ones).

The product of its digits is 4608, while the sum is 26.

The square root of 642644 is about 801.6507967937. The cubic root of 642644 is about 86.2958979963.

The spelling of 642644 in words is "six hundred forty-two thousand, six hundred forty-four".