1605686647120 has 80 divisors (see below), whose sum is σ = 3798516946320. Its totient is φ = 631063756800.

The previous prime is 1605686647109. The next prime is 1605686647139. The reversal of 1605686647120 is 217466865061.

It can be written as a sum of positive squares in 8 ways, for example, as 268444189456 + 1337242457664 = 518116^2 + 1156392^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4356430 + ... + 4710610.

It is an arithmetic number, because the mean of its divisors is an integer number (47481461829).

Almost surely, 2^{1605686647120} is an apocalyptic number.

1605686647120 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 1605686647120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1899258473160).

1605686647120 is an abundant number, since it is smaller than the sum of its proper divisors (2192830299200).

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

1605686647120 is a wasteful number, since it uses less digits than its factorization.

1605686647120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355184 (or 355178 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 1605686647120 in words is "one trillion, six hundred five billion, six hundred eighty-six million, six hundred forty-seven thousand, one hundred twenty".