1661944644360 has 2304 divisors, whose sum is σ = 7782870251520. Its totient is φ = 301916160000.

The previous prime is 1661944644359. The next prime is 1661944644361. The reversal of 1661944644360 is 634464491661.

1661944644360 is a `hidden beast` number, since 1 + 6 + 6 + 194 + 4 + 6 + 443 + 6 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1661944644359) and next prime (1661944644361).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1661944644297 and 1661944644306.

It is not an unprimeable number, because it can be changed into a prime (1661944644361) by changing a digit.

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 575 ways as a sum of consecutive naturals, for example, 4144500160 + ... + 4144500560.

It is an arithmetic number, because the mean of its divisors is an integer number (3377981880).

Almost surely, 2^{1661944644360} is an apocalyptic number.

1661944644360 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 1661944644360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3891435125760).

1661944644360 is an abundant number, since it is smaller than the sum of its proper divisors (6120925607160).

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

1661944644360 is a wasteful number, since it uses less digits than its factorization.

1661944644360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 540 (or 526 counting only the distinct ones).

The product of its (nonzero) digits is 8957952, while the sum is 54.

The spelling of 1661944644360 in words is "one trillion, six hundred sixty-one billion, nine hundred forty-four million, six hundred forty-four thousand, three hundred sixty".