1664728451424 has 288 divisors, whose sum is σ = 5128791333120. Its totient is φ = 530168550912.

The previous prime is 1664728451417. The next prime is 1664728451443. The reversal of 1664728451424 is 4241548274661.

1664728451424 is a `hidden beast` number, since 1 + 6 + 6 + 47 + 2 + 84 + 514 + 2 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 169364142 + ... + 169373970.

It is an arithmetic number, because the mean of its divisors is an integer number (17808303240).

Almost surely, 2^{1664728451424} 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 1664728451424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2564395666560).

1664728451424 is an abundant number, since it is smaller than the sum of its proper divisors (3464062881696).

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

1664728451424 is an equidigital number, since it uses as much as digits as its factorization.

1664728451424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10824 (or 10804 counting only the distinct ones).

The product of its digits is 10321920, while the sum is 54.

The spelling of 1664728451424 in words is "one trillion, six hundred sixty-four billion, seven hundred twenty-eight million, four hundred fifty-one thousand, four hundred twenty-four".