1561660611055 has 8 divisors (see below), whose sum is σ = 1896570959472. Its totient is φ = 1234276338048.

The previous prime is 1561660611031. The next prime is 1561660611109. The reversal of 1561660611055 is 5501160661651.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1561660611055 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 1881518394 + ... + 1881519223.

It is an arithmetic number, because the mean of its divisors is an integer number (237071369934).

Almost surely, 2^{1561660611055} is an apocalyptic number.

1561660611055 is a deficient number, since it is larger than the sum of its proper divisors (334910348417).

1561660611055 is an equidigital number, since it uses as much as digits as its factorization.

1561660611055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3763037705.

The product of its (nonzero) digits is 162000, while the sum is 43.

The spelling of 1561660611055 in words is "one trillion, five hundred sixty-one billion, six hundred sixty million, six hundred eleven thousand, fifty-five".