561698776645 has 4 divisors (see below), whose sum is σ = 674038531980. Its totient is φ = 449359021312.

The previous prime is 561698776591. The next prime is 561698776669. The reversal of 561698776645 is 546677896165.

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 75937171489 + 485761605156 = 275567^2 + 696966^2 .

It is a cyclic number.

It is not a de Polignac number, because 561698776645 - 2²⁷ = 561564558917 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56169877660 + ... + 56169877669.

It is an arithmetic number, because the mean of its divisors is an integer number (168509632995).

Almost surely, 2^561698776645 is an apocalyptic number.

It is an amenable number.

561698776645 is a deficient number, since it is larger than the sum of its proper divisors (112339755335).

561698776645 is a wasteful number, since it uses less digits than its factorization.

561698776645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112339755334.

The product of its digits is 457228800, while the sum is 70.

The spelling of 561698776645 in words is "five hundred sixty-one billion, six hundred ninety-eight million, seven hundred seventy-six thousand, six hundred forty-five".