642408 has 64 divisors (see below), whose sum is σ = 1814400. Its totient is φ = 188160.

The previous prime is 642407. The next prime is 642419. The reversal of 642408 is 804246.

642408 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642403) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9013 + ... + 9083.

It is an arithmetic number, because the mean of its divisors is an integer number (28350).

2⁶⁴²⁴⁰⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907200).

642408 is an abundant number, since it is smaller than the sum of its proper divisors (1171992).

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

642408 is a wasteful number, since it uses less digits than its factorization.

642408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 642408 is about 801.5035870163. The cubic root of 642408 is about 86.2853331395.

The spelling of 642408 in words is "six hundred forty-two thousand, four hundred eight".