861189644521 has 8 divisors (see below), whose sum is σ = 869434435584. Its totient is φ = 852967725120.

The previous prime is 861189644507. The next prime is 861189644593. The reversal of 861189644521 is 125446981168.

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 861189644521 - 2¹⁵ = 861189611753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861189645521) 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 7 ways as a sum of consecutive naturals, for example, 5642245 + ... + 5792866.

It is an arithmetic number, because the mean of its divisors is an integer number (108679304448).

Almost surely, 2^861189644521 is an apocalyptic number.

It is an amenable number.

861189644521 is a deficient number, since it is larger than the sum of its proper divisors (8244791063).

861189644521 is a wasteful number, since it uses less digits than its factorization.

861189644521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11435831.

The product of its digits is 3317760, while the sum is 55.

The spelling of 861189644521 in words is "eight hundred sixty-one billion, one hundred eighty-nine million, six hundred forty-four thousand, five hundred twenty-one".