1065605561 has 4 divisors (see below), whose sum is σ = 1067478900. Its totient is φ = 1063732224.

The previous prime is 1065605537. The next prime is 1065605579. The reversal of 1065605561 is 1655065601.

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 430313536 + 635292025 = 20744^2 + 25205^2 .

It is a cyclic number.

It is not a de Polignac number, because 1065605561 - 2¹⁴ = 1065589177 is a prime.

It is a super-2 number, since 2×1065605561² = 2271030423268249442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1065655561) by changing a digit.

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, 935816 + ... + 936953.

It is an arithmetic number, because the mean of its divisors is an integer number (266869725).

Almost surely, 2^1065605561 is an apocalyptic number.

It is an amenable number.

1065605561 is a deficient number, since it is larger than the sum of its proper divisors (1873339).

1065605561 is an equidigital number, since it uses as much as digits as its factorization.

1065605561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1873338.

The product of its (nonzero) digits is 27000, while the sum is 35.

The square root of 1065605561 is about 32643.6143985313. The cubic root of 1065605561 is about 1021.4069910821.

The spelling of 1065605561 in words is "one billion, sixty-five million, six hundred five thousand, five hundred sixty-one".