2181686816 has 24 divisors (see below), whose sum is σ = 4296965904. Its totient is φ = 1090393920.

The previous prime is 2181686809. The next prime is 2181686851. The reversal of 2181686816 is 6186861812.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73151 + ... + 98561.

It is an arithmetic number, because the mean of its divisors is an integer number (179040246).

Almost surely, 2^2181686816 is an apocalyptic number.

It is an amenable number.

2181686816 is a deficient number, since it is larger than the sum of its proper divisors (2115279088).

2181686816 is a wasteful number, since it uses less digits than its factorization.

2181686816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28104 (or 28096 counting only the distinct ones).

The product of its digits is 221184, while the sum is 47.

The square root of 2181686816 is about 46708.5304414515. The cubic root of 2181686816 is about 1296.9726034992.

The spelling of 2181686816 in words is "two billion, one hundred eighty-one million, six hundred eighty-six thousand, eight hundred sixteen".