1643723704920 has 512 divisors, whose sum is σ = 5807858319360. Its totient is φ = 368003328000.

The previous prime is 1643723704873. The next prime is 1643723704969. The reversal of 1643723704920 is 294073273461.

It is a self number, because there is not a number n which added to its sum of digits gives 1643723704920.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 462107782 + ... + 462111338.

It is an arithmetic number, because the mean of its divisors is an integer number (11343473280).

Almost surely, 2^{1643723704920} is an apocalyptic number.

1643723704920 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 1643723704920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2903929159680).

1643723704920 is an abundant number, since it is smaller than the sum of its proper divisors (4164134614440).

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

1643723704920 is a wasteful number, since it uses less digits than its factorization.

1643723704920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4127 (or 4123 counting only the distinct ones).

The product of its (nonzero) digits is 1524096, while the sum is 48.

The spelling of 1643723704920 in words is "one trillion, six hundred forty-three billion, seven hundred twenty-three million, seven hundred four thousand, nine hundred twenty".