1661920745184 has 240 divisors, whose sum is σ = 5587332857568. Its totient is φ = 474712731648.

The previous prime is 1661920745179. The next prime is 1661920745203. The reversal of 1661920745184 is 4815470291661.

1661920745184 is a `hidden beast` number, since 1 + 6 + 619 + 2 + 0 + 7 + 4 + 5 + 18 + 4 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1661920745184.

It is a congruent number.

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 39 ways as a sum of consecutive naturals, for example, 89567652 + ... + 89586204.

Almost surely, 2^{1661920745184} is an apocalyptic number.

1661920745184 is a gapful number since it is divisible by the number (14) 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 1661920745184, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2793666428784).

1661920745184 is an abundant number, since it is smaller than the sum of its proper divisors (3925412112384).

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

1661920745184 is a wasteful number, since it uses less digits than its factorization.

1661920745184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23519 (or 23502 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 1661920745184 in words is "one trillion, six hundred sixty-one billion, nine hundred twenty million, seven hundred forty-five thousand, one hundred eighty-four".