1643456279872 has 224 divisors, whose sum is σ = 3934083250944. Its totient is φ = 671947161600.

The previous prime is 1643456279863. The next prime is 1643456279891. The reversal of 1643456279872 is 2789726543461.

It is a Harshad number since it is a multiple of its sum of digits (64).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 526578472 + ... + 526581592.

It is an arithmetic number, because the mean of its divisors is an integer number (17562871656).

Almost surely, 2^{1643456279872} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643456279872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1967041625472).

1643456279872 is an abundant number, since it is smaller than the sum of its proper divisors (2290626971072).

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

1643456279872 is a wasteful number, since it uses less digits than its factorization.

1643456279872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5097 (or 5087 counting only the distinct ones).

The product of its digits is 121927680, while the sum is 64.

The spelling of 1643456279872 in words is "one trillion, six hundred forty-three billion, four hundred fifty-six million, two hundred seventy-nine thousand, eight hundred seventy-two".