861010561 has 4 divisors (see below), whose sum is σ = 861234624. Its totient is φ = 860786500.

The previous prime is 861010559. The next prime is 861010567. The reversal of 861010561 is 165010168.

861010561 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 861010561 - 2¹ = 861010559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861010567) 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, 106165 + ... + 113986.

It is an arithmetic number, because the mean of its divisors is an integer number (215308656).

Almost surely, 2^861010561 is an apocalyptic number.

It is an amenable number.

861010561 is a deficient number, since it is larger than the sum of its proper divisors (224063).

861010561 is a wasteful number, since it uses less digits than its factorization.

861010561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224062.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 861010561 is about 29342.9814606492. The cubic root of 861010561 is about 951.3408806650.

The spelling of 861010561 in words is "eight hundred sixty-one million, ten thousand, five hundred sixty-one".