805870561 has 4 divisors (see below), whose sum is σ = 805950000. Its totient is φ = 805791124.

The previous prime is 805870553. The next prime is 805870577. The reversal of 805870561 is 165078508.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 805870561 - 2³ = 805870553 is a prime.

It is a super-2 number, since 2×805870561² = 1298854722172909442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (805870511) 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, 21811 + ... + 45688.

It is an arithmetic number, because the mean of its divisors is an integer number (201487500).

Almost surely, 2^805870561 is an apocalyptic number.

It is an amenable number.

805870561 is a deficient number, since it is larger than the sum of its proper divisors (79439).

805870561 is a wasteful number, since it uses less digits than its factorization.

805870561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79438.

The product of its (nonzero) digits is 67200, while the sum is 40.

The square root of 805870561 is about 28387.8593944665. The cubic root of 805870561 is about 930.5829624364.

The spelling of 805870561 in words is "eight hundred five million, eight hundred seventy thousand, five hundred sixty-one".