1665056565 has 24 divisors (see below), whose sum is σ = 2889669120. Its totient is φ = 886931424.

The previous prime is 1665056557. The next prime is 1665056567. The reversal of 1665056565 is 5656505661.

It is not a de Polignac number, because 1665056565 - 2³ = 1665056557 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1665056565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665056567) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14556 + ... + 59514.

It is an arithmetic number, because the mean of its divisors is an integer number (120402880).

Almost surely, 2^1665056565 is an apocalyptic number.

1665056565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1665056565 is a deficient number, since it is larger than the sum of its proper divisors (1224612555).

1665056565 is a wasteful number, since it uses less digits than its factorization.

1665056565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45793 (or 45790 counting only the distinct ones).

The product of its (nonzero) digits is 810000, while the sum is 45.

The square root of 1665056565 is about 40805.1046439045. The cubic root of 1665056565 is about 1185.2491811616.

It can be divided in two parts, 166505656 and 5, that added together give a palindrome (166505661).

The spelling of 1665056565 in words is "one billion, six hundred sixty-five million, fifty-six thousand, five hundred sixty-five".