1643256848640 has 864 divisors, whose sum is σ = 6245291888640. Its totient is φ = 363803443200.

The previous prime is 1643256848591. The next prime is 1643256848669. The reversal of 1643256848640 is 468486523461.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

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, 6393995392 + ... + 6393995648.

Almost surely, 2^{1643256848640} is an apocalyptic number.

1643256848640 is a gapful number since it is divisible by the number (10) 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 1643256848640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3122645944320).

1643256848640 is an abundant number, since it is smaller than the sum of its proper divisors (4602035040000).

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

1643256848640 is a wasteful number, since it uses less digits than its factorization.

1643256848640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 26542080, while the sum is 57.

The spelling of 1643256848640 in words is "one trillion, six hundred forty-three billion, two hundred fifty-six million, eight hundred forty-eight thousand, six hundred forty".