561650165561 has 4 divisors (see below), whose sum is σ = 594688410612. Its totient is φ = 528611920512.

The previous prime is 561650165537. The next prime is 561650165563. The reversal of 561650165561 is 165561056165.

561650165561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 489256881961 + 72393283600 = 699469^2 + 269060^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561650165561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561650165563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16519122500 + ... + 16519122533.

It is an arithmetic number, because the mean of its divisors is an integer number (148672102653).

Almost surely, 2^561650165561 is an apocalyptic number.

It is an amenable number.

561650165561 is a deficient number, since it is larger than the sum of its proper divisors (33038245051).

561650165561 is a wasteful number, since it uses less digits than its factorization.

561650165561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33038245050.

The product of its (nonzero) digits is 810000, while the sum is 47.

The spelling of 561650165561 in words is "five hundred sixty-one billion, six hundred fifty million, one hundred sixty-five thousand, five hundred sixty-one".