1561709645280 has 288 divisors, whose sum is σ = 5690376147456. Its totient is φ = 389084838912.

The previous prime is 1561709645269. The next prime is 1561709645351. The reversal of 1561709645280 is 825469071651.

It is a happy number.

1561709645280 is a `hidden beast` number, since 1 + 56 + 1 + 7 + 0 + 9 + 64 + 528 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

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, 875869 + ... + 1972451.

It is an arithmetic number, because the mean of its divisors is an integer number (19758250512).

Almost surely, 2^{1561709645280} is an apocalyptic number.

1561709645280 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 1561709645280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2845188073728).

1561709645280 is an abundant number, since it is smaller than the sum of its proper divisors (4128666502176).

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

1561709645280 is a wasteful number, since it uses less digits than its factorization.

1561709645280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1096670 (or 1096659 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 1561709645280 in words is "one trillion, five hundred sixty-one billion, seven hundred nine million, six hundred forty-five thousand, two hundred eighty".