861911845 has 8 divisors (see below), whose sum is σ = 1036274976. Its totient is φ = 688208976.

The previous prime is 861911819. The next prime is 861911893. The reversal of 861911845 is 548119168.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-861911845 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162187 + ... + 167416.

It is an arithmetic number, because the mean of its divisors is an integer number (129534372).

Almost surely, 2^861911845 is an apocalyptic number.

It is an amenable number.

861911845 is a deficient number, since it is larger than the sum of its proper divisors (174363131).

861911845 is a wasteful number, since it uses less digits than its factorization.

861911845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330131.

The product of its digits is 69120, while the sum is 43.

The square root of 861911845 is about 29358.3351878134. The cubic root of 861911845 is about 951.6727114031.

The spelling of 861911845 in words is "eight hundred sixty-one million, nine hundred eleven thousand, eight hundred forty-five".