2167181987 has 2 divisors, whose sum is σ = 2167181988. Its totient is φ = 2167181986.

The previous prime is 2167181963. The next prime is 2167182001. The reversal of 2167181987 is 7891817612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2167181987 is a prime.

It is not a weakly prime, because it can be changed into another prime (2167181917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083590993 + 1083590994.

It is an arithmetic number, because the mean of its divisors is an integer number (1083590994).

Almost surely, 2^2167181987 is an apocalyptic number.

2167181987 is a deficient number, since it is larger than the sum of its proper divisors (1).

2167181987 is an equidigital number, since it uses as much as digits as its factorization.

2167181987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 338688, while the sum is 50.

The square root of 2167181987 is about 46553.0019117994. The cubic root of 2167181987 is about 1294.0919255190.

The spelling of 2167181987 in words is "two billion, one hundred sixty-seven million, one hundred eighty-one thousand, nine hundred eighty-seven".