861836857 has 4 divisors (see below), whose sum is σ = 984956416. Its totient is φ = 738717300.

The previous prime is 861836821. The next prime is 861836861. The reversal of 861836857 is 758638168.

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 a de Polignac number, because none of the positive numbers 2^k-861836857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861836897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61559769 + ... + 61559782.

It is an arithmetic number, because the mean of its divisors is an integer number (246239104).

Almost surely, 2^861836857 is an apocalyptic number.

It is an amenable number.

861836857 is a deficient number, since it is larger than the sum of its proper divisors (123119559).

861836857 is a wasteful number, since it uses less digits than its factorization.

861836857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123119558.

The product of its digits is 1935360, while the sum is 52.

The square root of 861836857 is about 29357.0580440207. The cubic root of 861836857 is about 951.6451114796.

The spelling of 861836857 in words is "eight hundred sixty-one million, eight hundred thirty-six thousand, eight hundred fifty-seven".