2181965987 has 2 divisors, whose sum is σ = 2181965988. Its totient is φ = 2181965986.

The previous prime is 2181965977. The next prime is 2181965993. The reversal of 2181965987 is 7895691812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2181965987 - 2⁴ = 2181965971 is a prime.

It is not a weakly prime, because it can be changed into another prime (2181965927) 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 as a sum of consecutive naturals, namely, 1090982993 + 1090982994.

It is an arithmetic number, because the mean of its divisors is an integer number (1090982994).

Almost surely, 2^2181965987 is an apocalyptic number.

2181965987 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181965987 is an equidigital number, since it uses as much as digits as its factorization.

2181965987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2177280, while the sum is 56.

The square root of 2181965987 is about 46711.5187828441. The cubic root of 2181965987 is about 1297.0279218112.

The spelling of 2181965987 in words is "two billion, one hundred eighty-one million, nine hundred sixty-five thousand, nine hundred eighty-seven".