86381991 has 8 divisors (see below), whose sum is σ = 127973360. Its totient is φ = 57587976.

The previous prime is 86381989. The next prime is 86381993. The reversal of 86381991 is 19918368.

86381991 is a `hidden beast` number, since 8 + 638 + 1 + 9 + 9 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (86381989) and next prime (86381993).

It is not a de Polignac number, because 86381991 - 2¹ = 86381989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86381993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1599640 + ... + 1599693.

It is an arithmetic number, because the mean of its divisors is an integer number (15996670).

Almost surely, 2^86381991 is an apocalyptic number.

86381991 is a deficient number, since it is larger than the sum of its proper divisors (41591369).

86381991 is a wasteful number, since it uses less digits than its factorization.

86381991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3199342 (or 3199336 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 86381991 is about 9294.1912504532. The cubic root of 86381991 is about 442.0530620899.

The spelling of 86381991 in words is "eighty-six million, three hundred eighty-one thousand, nine hundred ninety-one".