855191671987 has 2 divisors, whose sum is σ = 855191671988. Its totient is φ = 855191671986.

The previous prime is 855191671949. The next prime is 855191672039. The reversal of 855191671987 is 789176191558.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-855191671987 is a prime.

It is not a weakly prime, because it can be changed into another prime (855191671787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427595835993 + 427595835994.

It is an arithmetic number, because the mean of its divisors is an integer number (427595835994).

Almost surely, 2^855191671987 is an apocalyptic number.

855191671987 is a deficient number, since it is larger than the sum of its proper divisors (1).

855191671987 is an equidigital number, since it uses as much as digits as its factorization.

855191671987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38102400, while the sum is 67.

The spelling of 855191671987 in words is "eight hundred fifty-five billion, one hundred ninety-one million, six hundred seventy-one thousand, nine hundred eighty-seven".