845206561 has 4 divisors (see below), whose sum is σ = 894924612. Its totient is φ = 795488512.

The previous prime is 845206489. The next prime is 845206573. The reversal of 845206561 is 165602548.

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 495329536 + 349877025 = 22256^2 + 18705^2 .

It is a cyclic number.

It is not a de Polignac number, because 845206561 - 2¹¹ = 845204513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 845206561.

It is not an unprimeable number, because it can be changed into a prime (845206591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24859000 + ... + 24859033.

It is an arithmetic number, because the mean of its divisors is an integer number (223731153).

Almost surely, 2^845206561 is an apocalyptic number.

It is an amenable number.

845206561 is a deficient number, since it is larger than the sum of its proper divisors (49718051).

845206561 is a wasteful number, since it uses less digits than its factorization.

845206561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49718050.

The product of its (nonzero) digits is 57600, while the sum is 37.

The square root of 845206561 is about 29072.4364476045. The cubic root of 845206561 is about 945.4842235313.

The spelling of 845206561 in words is "eight hundred forty-five million, two hundred six thousand, five hundred sixty-one".