2165427881 has 2 divisors, whose sum is σ = 2165427882. Its totient is φ = 2165427880.

The previous prime is 2165427871. The next prime is 2165427911. The reversal of 2165427881 is 1887245612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2117472256 + 47955625 = 46016^2 + 6925^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2165427881 is a prime.

It is a super-2 number, since 2×2165427881² = 9378155815624300322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2165427821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1082713940 + 1082713941.

It is an arithmetic number, because the mean of its divisors is an integer number (1082713941).

Almost surely, 2^2165427881 is an apocalyptic number.

It is an amenable number.

2165427881 is a deficient number, since it is larger than the sum of its proper divisors (1).

2165427881 is an equidigital number, since it uses as much as digits as its factorization.

2165427881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 215040, while the sum is 44.

The square root of 2165427881 is about 46534.1582173783. The cubic root of 2165427881 is about 1293.7426874862.

The spelling of 2165427881 in words is "two billion, one hundred sixty-five million, four hundred twenty-seven thousand, eight hundred eighty-one".