2161987 has 2 divisors, whose sum is σ = 2161988. Its totient is φ = 2161986.

The previous prime is 2161967. The next prime is 2162003. The reversal of 2161987 is 7891612.

It is a happy number.

2161987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161987 is a prime.

It is not a weakly prime, because it can be changed into another prime (2161927) 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, 1080993 + 1080994.

It is an arithmetic number, because the mean of its divisors is an integer number (1080994).

2^2161987 is an apocalyptic number.

2161987 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161987 is an equidigital number, since it uses as much as digits as its factorization.

2161987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 34.

The square root of 2161987 is about 1470.3696814067. The cubic root of 2161987 is about 129.3057068624.

The spelling of 2161987 in words is "two million, one hundred sixty-one thousand, nine hundred eighty-seven".