1661417328384 has 432 divisors, whose sum is σ = 5360504333184. Its totient is φ = 490536345600.

The previous prime is 1661417328371. The next prime is 1661417328401. The reversal of 1661417328384 is 4838237141661.

1661417328384 is a `hidden beast` number, since 1 + 6 + 614 + 17 + 3 + 2 + 8 + 3 + 8 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 1661417328384.

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, 502392459 + ... + 502395765.

Almost surely, 2^{1661417328384} 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 1661417328384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2680252166592).

1661417328384 is an abundant number, since it is smaller than the sum of its proper divisors (3699087004800).

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

1661417328384 is a wasteful number, since it uses less digits than its factorization.

1661417328384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3844 (or 3827 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 54.

The spelling of 1661417328384 in words is "one trillion, six hundred sixty-one billion, four hundred seventeen million, three hundred twenty-eight thousand, three hundred eighty-four".