1661501782160 has 80 divisors (see below), whose sum is σ = 4397397655680. Its totient is φ = 577913656320.

The previous prime is 1661501782159. The next prime is 1661501782169. The reversal of 1661501782160 is 612871051661.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (1661501782169) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 41024765 + ... + 41065244.

It is an arithmetic number, because the mean of its divisors is an integer number (54967470696).

Almost surely, 2^{1661501782160} is an apocalyptic number.

1661501782160 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661501782160 is an abundant number, since it is smaller than the sum of its proper divisors (2735895873520).

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

1661501782160 is a wasteful number, since it uses less digits than its factorization.

1661501782160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82090056 (or 82090050 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 44.

The spelling of 1661501782160 in words is "one trillion, six hundred sixty-one billion, five hundred one million, seven hundred eighty-two thousand, one hundred sixty".