646144 has 22 divisors (see below), whose sum is σ = 1293704. Its totient is φ = 322560.

The previous prime is 646103. The next prime is 646147. The reversal of 646144 is 441646.

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 pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 709 + ... + 1339.

2⁶⁴⁶¹⁴⁴ is an apocalyptic number.

646144 is a gapful number since it is divisible by the number (64) 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 646144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (646852).

646144 is an abundant number, since it is smaller than the sum of its proper divisors (647560).

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

646144 is an equidigital number, since it uses as much as digits as its factorization.

646144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 651 (or 633 counting only the distinct ones).

The product of its digits is 2304, while the sum is 25.

The square root of 646144 is about 803.8308279732. The cubic root of 646144 is about 86.4522774617.

The spelling of 646144 in words is "six hundred forty-six thousand, one hundred forty-four".