2181167987 has 2 divisors, whose sum is σ = 2181167988. Its totient is φ = 2181167986.

The previous prime is 2181167969. The next prime is 2181168007. The reversal of 2181167987 is 7897611812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2181167987 - 2¹² = 2181163891 is a prime.

It is not a weakly prime, because it can be changed into another prime (2181160987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090583993 + 1090583994.

It is an arithmetic number, because the mean of its divisors is an integer number (1090583994).

Almost surely, 2^2181167987 is an apocalyptic number.

2181167987 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181167987 is an equidigital number, since it uses as much as digits as its factorization.

2181167987 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2181167987 is about 46702.9762113722. The cubic root of 2181167987 is about 1296.8697839221.

It can be divided in two parts, 21811 and 67987, that added together give a palindrome (89798).

The spelling of 2181167987 in words is "two billion, one hundred eighty-one million, one hundred sixty-seven thousand, nine hundred eighty-seven".