1644618168 has 112 divisors (see below), whose sum is σ = 4687920720. Its totient is φ = 540556416.

The previous prime is 1644618167. The next prime is 1644618251. The reversal of 1644618168 is 8618164461.

1644618168 is a `hidden beast` number, since 16 + 4 + 4 + 618 + 16 + 8 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644618167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 423805 + ... + 427667.

It is an arithmetic number, because the mean of its divisors is an integer number (41856435).

Almost surely, 2^1644618168 is an apocalyptic number.

1644618168 is a gapful number since it is divisible by the number (18) 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 1644618168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2343960360).

1644618168 is an abundant number, since it is smaller than the sum of its proper divisors (3043302552).

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

1644618168 is an equidigital number, since it uses as much as digits as its factorization.

1644618168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3960 (or 3941 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 1644618168 is about 40553.8921436648. The cubic root of 1644618168 is about 1180.3795982595.

The spelling of 1644618168 in words is "one billion, six hundred forty-four million, six hundred eighteen thousand, one hundred sixty-eight".