642040 has 32 divisors (see below), whose sum is σ = 1651680. Its totient is φ = 220032.

The previous prime is 642013. The next prime is 642049. The reversal of 642040 is 40246.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 867 + ... + 1426.

It is an arithmetic number, because the mean of its divisors is an integer number (51615).

2⁶⁴²⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

642040 is an abundant number, since it is smaller than the sum of its proper divisors (1009640).

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

642040 is a wasteful number, since it uses less digits than its factorization.

642040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2311 (or 2307 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 642040 is about 801.2739856004. The cubic root of 642040 is about 86.2688539613.

Adding to 642040 its reverse (40246), we get a palindrome (682286).

The spelling of 642040 in words is "six hundred forty-two thousand, forty".