861391843 has 8 divisors (see below), whose sum is σ = 959641200. Its totient is φ = 767712288.

The previous prime is 861391841. The next prime is 861391873. The reversal of 861391843 is 348193168.

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

It is a cyclic number.

It is not a de Polignac number, because 861391843 - 2¹ = 861391841 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 861391843.

It is not an unprimeable number, because it can be changed into a prime (861391841) by changing a digit.

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, 1142053 + ... + 1142806.

It is an arithmetic number, because the mean of its divisors is an integer number (119955150).

Almost surely, 2^861391843 is an apocalyptic number.

861391843 is a deficient number, since it is larger than the sum of its proper divisors (98249357).

861391843 is a wasteful number, since it uses less digits than its factorization.

861391843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2284901.

The product of its digits is 124416, while the sum is 43.

The square root of 861391843 is about 29349.4777295951. The cubic root of 861391843 is about 951.4812876242.

The spelling of 861391843 in words is "eight hundred sixty-one million, three hundred ninety-one thousand, eight hundred forty-three".