1661565606116 has 24 divisors (see below), whose sum is σ = 3131487643704. Its totient is φ = 766857934080.

The previous prime is 1661565606109. The next prime is 1661565606131. The reversal of 1661565606116 is 6116065651661.

It can be written as a sum of positive squares in 4 ways, for example, as 663268516 + 1660902337600 = 25754^2 + 1288760^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1922546 + ... + 2649398.

It is an arithmetic number, because the mean of its divisors is an integer number (130478651821).

Almost surely, 2^{1661565606116} is an apocalyptic number.

It is an amenable number.

1661565606116 is a deficient number, since it is larger than the sum of its proper divisors (1469922037588).

1661565606116 is a wasteful number, since it uses less digits than its factorization.

1661565606116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770831 (or 770829 counting only the distinct ones).

The product of its (nonzero) digits is 1166400, while the sum is 50.

The spelling of 1661565606116 in words is "one trillion, six hundred sixty-one billion, five hundred sixty-five million, six hundred six thousand, one hundred sixteen".