855645565 has 4 divisors (see below), whose sum is σ = 1026774684. Its totient is φ = 684516448.

The previous prime is 855645559. The next prime is 855645607. The reversal of 855645565 is 565546558.

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 161112249 + 694533316 = 12693^2 + 26354^2 .

It is a cyclic number.

It is not a de Polignac number, because 855645565 - 2⁹ = 855645053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85564552 + ... + 85564561.

It is an arithmetic number, because the mean of its divisors is an integer number (256693671).

Almost surely, 2^855645565 is an apocalyptic number.

It is an amenable number.

855645565 is a deficient number, since it is larger than the sum of its proper divisors (171129119).

855645565 is a wasteful number, since it uses less digits than its factorization.

855645565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171129118.

The product of its digits is 3600000, while the sum is 49.

The square root of 855645565 is about 29251.4198800674. The cubic root of 855645565 is about 949.3608128771.

The spelling of 855645565 in words is "eight hundred fifty-five million, six hundred forty-five thousand, five hundred sixty-five".