1986665867 has 2 divisors, whose sum is σ = 1986665868. Its totient is φ = 1986665866.

The previous prime is 1986665819. The next prime is 1986665869. The reversal of 1986665867 is 7685666891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1986665867 - 2²² = 1982471563 is a prime.

Together with 1986665869, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1986665869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 993332933 + 993332934.

It is an arithmetic number, because the mean of its divisors is an integer number (993332934).

Almost surely, 2^1986665867 is an apocalyptic number.

1986665867 is a deficient number, since it is larger than the sum of its proper divisors (1).

1986665867 is an equidigital number, since it uses as much as digits as its factorization.

1986665867 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26127360, while the sum is 62.

The square root of 1986665867 is about 44572.0300973604. The cubic root of 1986665867 is about 1257.1148116905.

The spelling of 1986665867 in words is "one billion, nine hundred eighty-six million, six hundred sixty-five thousand, eight hundred sixty-seven".