8641785861 has 32 divisors (see below), whose sum is σ = 12918407040. Its totient is φ = 5709225600.

The previous prime is 8641785857. The next prime is 8641785863. The reversal of 8641785861 is 1685871468.

It is a happy number.

It is not a de Polignac number, because 8641785861 - 2² = 8641785857 is a prime.

It is a super-2 number, since 2×8641785861² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 8641785798 and 8641785807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8641785863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3610081 + ... + 3612473.

It is an arithmetic number, because the mean of its divisors is an integer number (403700220).

Almost surely, 2^8641785861 is an apocalyptic number.

It is an amenable number.

8641785861 is a deficient number, since it is larger than the sum of its proper divisors (4276621179).

8641785861 is a wasteful number, since it uses less digits than its factorization.

8641785861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3554 (or 3548 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 54.

The square root of 8641785861 is about 92961.2062152810. The cubic root of 8641785861 is about 2052.1125049461.

The spelling of 8641785861 in words is "eight billion, six hundred forty-one million, seven hundred eighty-five thousand, eight hundred sixty-one".