987678191 has 2 divisors, whose sum is σ = 987678192. Its totient is φ = 987678190.

The previous prime is 987678187. The next prime is 987678217. The reversal of 987678191 is 191876789.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 987678191 - 2² = 987678187 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987638191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493839095 + 493839096.

It is an arithmetic number, because the mean of its divisors is an integer number (493839096).

Almost surely, 2^987678191 is an apocalyptic number.

987678191 is a deficient number, since it is larger than the sum of its proper divisors (1).

987678191 is an equidigital number, since it uses as much as digits as its factorization.

987678191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1524096, while the sum is 56.

The square root of 987678191 is about 31427.3478200118. The cubic root of 987678191 is about 995.8757442315.

The spelling of 987678191 in words is "nine hundred eighty-seven million, six hundred seventy-eight thousand, one hundred ninety-one".