1561185982776 has 512 divisors, whose sum is σ = 4878720000000. Its totient is φ = 414919895040.

The previous prime is 1561185982753. The next prime is 1561185982801. The reversal of 1561185982776 is 6772895811651.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3128628975 + ... + 3128629473.

It is an arithmetic number, because the mean of its divisors is an integer number (9528750000).

Almost surely, 2^{1561185982776} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561185982776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2439360000000).

1561185982776 is an abundant number, since it is smaller than the sum of its proper divisors (3317534017224).

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

1561185982776 is a wasteful number, since it uses less digits than its factorization.

1561185982776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872 (or 854 counting only the distinct ones).

The product of its digits is 50803200, while the sum is 66.

The spelling of 1561185982776 in words is "one trillion, five hundred sixty-one billion, one hundred eighty-five million, nine hundred eighty-two thousand, seven hundred seventy-six".