1665265559 has 4 divisors (see below), whose sum is σ = 1675872504. Its totient is φ = 1654658616.

The previous prime is 1665265543. The next prime is 1665265577. The reversal of 1665265559 is 9555625661.

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

It is a cyclic number.

It is not a de Polignac number, because 1665265559 - 2⁴ = 1665265543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665265759) 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, 5303237 + ... + 5303550.

It is an arithmetic number, because the mean of its divisors is an integer number (418968126).

Almost surely, 2^1665265559 is an apocalyptic number.

1665265559 is a deficient number, since it is larger than the sum of its proper divisors (10606945).

1665265559 is a wasteful number, since it uses less digits than its factorization.

1665265559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10606944.

The product of its digits is 2430000, while the sum is 50.

The square root of 1665265559 is about 40807.6654441295. The cubic root of 1665265559 is about 1185.2987689873.

The spelling of 1665265559 in words is "one billion, six hundred sixty-five million, two hundred sixty-five thousand, five hundred fifty-nine".