646140 has 72 divisors (see below), whose sum is σ = 2010960. Its totient is φ = 154880.

The previous prime is 646103. The next prime is 646147. The reversal of 646140 is 41646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646147) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7216 + ... + 7304.

It is an arithmetic number, because the mean of its divisors is an integer number (27930).

2⁶⁴⁶¹⁴⁰ is an apocalyptic number.

646140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1005480).

646140 is an abundant number, since it is smaller than the sum of its proper divisors (1364820).

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

646140 is a wasteful number, since it uses less digits than its factorization.

646140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 110 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 646140 is about 803.8283398836. The cubic root of 646140 is about 86.4520990650.

Adding to 646140 its reverse (41646), we get a palindrome (687786).

The spelling of 646140 in words is "six hundred forty-six thousand, one hundred forty".