1664728251680 has 192 divisors, whose sum is σ = 4252869992448. Its totient is φ = 612146626560.

The previous prime is 1664728251677. The next prime is 1664728251707. The reversal of 1664728251680 is 861528274661.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 770349800 + ... + 770351960.

It is an arithmetic number, because the mean of its divisors is an integer number (22150364544).

Almost surely, 2^{1664728251680} is an apocalyptic number.

1664728251680 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 1664728251680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2126434996224).

1664728251680 is an abundant number, since it is smaller than the sum of its proper divisors (2588141740768).

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

1664728251680 is a wasteful number, since it uses less digits than its factorization.

1664728251680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3539 (or 3531 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 56.

The spelling of 1664728251680 in words is "one trillion, six hundred sixty-four billion, seven hundred twenty-eight million, two hundred fifty-one thousand, six hundred eighty".