861081861 has 8 divisors (see below), whose sum is σ = 1148865184. Its totient is φ = 573676560.

The previous prime is 861081857. The next prime is 861081869. The reversal of 861081861 is 168180168.

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

It is not a de Polignac number, because 861081861 - 2² = 861081857 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861081869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89146 + ... + 98331.

It is an arithmetic number, because the mean of its divisors is an integer number (143608148).

Almost surely, 2^861081861 is an apocalyptic number.

It is an amenable number.

861081861 is a deficient number, since it is larger than the sum of its proper divisors (287783323).

861081861 is a wasteful number, since it uses less digits than its factorization.

861081861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189011.

The product of its (nonzero) digits is 18432, while the sum is 39.

The square root of 861081861 is about 29344.1963767966. The cubic root of 861081861 is about 951.3671400148.

The spelling of 861081861 in words is "eight hundred sixty-one million, eighty-one thousand, eight hundred sixty-one".