800561 has 4 divisors (see below), whose sum is σ = 835392. Its totient is φ = 765732.

The previous prime is 800557. The next prime is 800573. The reversal of 800561 is 165008.

800561 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 800561 - 2² = 800557 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (800521) 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, 17381 + ... + 17426.

It is an arithmetic number, because the mean of its divisors is an integer number (208848).

2⁸⁰⁰⁵⁶¹ is an apocalyptic number.

It is an amenable number.

800561 is a deficient number, since it is larger than the sum of its proper divisors (34831).

800561 is a wasteful number, since it uses less digits than its factorization.

800561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34830.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 800561 is about 894.7407445735. The cubic root of 800561 is about 92.8534710298.

Adding to 800561 its reverse (165008), we get a palindrome (965569).

The spelling of 800561 in words is "eight hundred thousand, five hundred sixty-one".