850561 has 4 divisors (see below), whose sum is σ = 900612. Its totient is φ = 800512.

The previous prime is 850537. The next prime is 850567. The reversal of 850561 is 165058.

850561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165058 = 2 ⋅82529.

It can be written as a sum of positive squares in 2 ways, for example, as 297025 + 553536 = 545^2 + 744^2 .

It is a cyclic number.

It is not a de Polignac number, because 850561 - 2⁵ = 850529 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

850561 is a modest number, since divided by 561 gives 85 as remainder.

It is not an unprimeable number, because it can be changed into a prime (850567) 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, 25000 + ... + 25033.

It is an arithmetic number, because the mean of its divisors is an integer number (225153).

2⁸⁵⁰⁵⁶¹ is an apocalyptic number.

It is an amenable number.

850561 is a deficient number, since it is larger than the sum of its proper divisors (50051).

850561 is a wasteful number, since it uses less digits than its factorization.

850561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50050.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 850561 is about 922.2586405125. The cubic root of 850561 is about 94.7476590367.

The spelling of 850561 in words is "eight hundred fifty thousand, five hundred sixty-one".