661055115605 has 8 divisors (see below), whose sum is σ = 793470770232. Its totient is φ = 528707671488.

The previous prime is 661055115559. The next prime is 661055115607. The reversal of 661055115605 is 506511550166.

It can be written as a sum of positive squares in 4 ways, for example, as 37267916401 + 623787199204 = 193049^2 + 789802^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661055115605 - 2⁸ = 661055115349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661055115607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17031302 + ... + 17070071.

It is an arithmetic number, because the mean of its divisors is an integer number (99183846279).

Almost surely, 2^661055115605 is an apocalyptic number.

It is an amenable number.

661055115605 is a deficient number, since it is larger than the sum of its proper divisors (132415654627).

661055115605 is a wasteful number, since it uses less digits than its factorization.

661055115605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34105255.

The product of its (nonzero) digits is 135000, while the sum is 41.

The spelling of 661055115605 in words is "six hundred sixty-one billion, fifty-five million, one hundred fifteen thousand, six hundred five".