1644649599168 has 42 divisors (see below), whose sum is σ = 4714091127044. Its totient is φ = 548216532864.

The previous prime is 1644649599163. The next prime is 1644649599169. The reversal of 1644649599168 is 8619959464461.

It is a happy number.

1644649599168 is a `hidden beast` number, since 1 + 6 + 4 + 46 + 495 + 9 + 91 + 6 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 1644649599096 and 1644649599105.

It is not an unprimeable number, because it can be changed into a prime (1644649599163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1427646646 + ... + 1427647797.

Almost surely, 2^{1644649599168} is an apocalyptic number.

1644649599168 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1644649599168 is an abundant number, since it is smaller than the sum of its proper divisors (3069441527876).

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

1644649599168 is a wasteful number, since it uses less digits than its factorization.

1644649599168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2855294461 (or 2855294448 counting only the distinct ones).

The product of its digits is 403107840, while the sum is 72.

The spelling of 1644649599168 in words is "one trillion, six hundred forty-four billion, six hundred forty-nine million, five hundred ninety-nine thousand, one hundred sixty-eight".