2185881861 has 8 divisors (see below), whose sum is σ = 2914932064. Its totient is φ = 1457043120.

The previous prime is 2185881857. The next prime is 2185881883. The reversal of 2185881861 is 1681885812.

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

It is not a de Polignac number, because 2185881861 - 2² = 2185881857 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 2185881861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2185881461) 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, 26926 + ... + 71391.

It is an arithmetic number, because the mean of its divisors is an integer number (364366508).

Almost surely, 2^2185881861 is an apocalyptic number.

It is an amenable number.

2185881861 is a deficient number, since it is larger than the sum of its proper divisors (729050203).

2185881861 is an equidigital number, since it uses as much as digits as its factorization.

2185881861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105731.

The product of its digits is 245760, while the sum is 48.

The square root of 2185881861 is about 46753.4155009022. The cubic root of 2185881861 is about 1297.8033635649.

The spelling of 2185881861 in words is "two billion, one hundred eighty-five million, eight hundred eighty-one thousand, eight hundred sixty-one".