1644031288368 has 480 divisors, whose sum is σ = 5551985094656. Its totient is φ = 444300982272.

The previous prime is 1644031288343. The next prime is 1644031288441. The reversal of 1644031288368 is 8638821304461.

It is a happy number.

1644031288368 is a `hidden beast` number, since 16 + 440 + 3 + 128 + 8 + 3 + 68 = 666.

It is a super-3 number, since 3×1644031288368³ (a number of 38 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 357629046 + ... + 357633642.

Almost surely, 2^{1644031288368} is an apocalyptic number.

1644031288368 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 1644031288368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2775992547328).

1644031288368 is an abundant number, since it is smaller than the sum of its proper divisors (3907953806288).

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

1644031288368 is a wasteful number, since it uses less digits than its factorization.

1644031288368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4921 (or 4912 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 54.

The spelling of 1644031288368 in words is "one trillion, six hundred forty-four billion, thirty-one million, two hundred eighty-eight thousand, three hundred sixty-eight".