565515505561 has 4 divisors (see below), whose sum is σ = 580799708452. Its totient is φ = 550231302672.

The previous prime is 565515505543. The next prime is 565515505567. The reversal of 565515505561 is 165505515565.

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 316383750400 + 249131755161 = 562480^2 + 499131^2 .

It is a cyclic number.

It is not a de Polignac number, because 565515505561 - 2¹⁵ = 565515472793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (565515505567) 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, 7642101390 + ... + 7642101463.

It is an arithmetic number, because the mean of its divisors is an integer number (145199927113).

Almost surely, 2^565515505561 is an apocalyptic number.

It is an amenable number.

565515505561 is a deficient number, since it is larger than the sum of its proper divisors (15284202891).

565515505561 is a wasteful number, since it uses less digits than its factorization.

565515505561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15284202890.

The product of its (nonzero) digits is 2812500, while the sum is 49.

The spelling of 565515505561 in words is "five hundred sixty-five billion, five hundred fifteen million, five hundred five thousand, five hundred sixty-one".