86186781 has 16 divisors (see below), whose sum is σ = 127960000. Its totient is φ = 57333744.

The previous prime is 86186777. The next prime is 86186791. The reversal of 86186781 is 18768168.

It is not a de Polignac number, because 86186781 - 2² = 86186777 is a prime.

It is a super-2 number, since 2×86186781² = 14856322438283922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86186761) 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 15 ways as a sum of consecutive naturals, for example, 10275 + ... + 16671.

It is an arithmetic number, because the mean of its divisors is an integer number (7997500).

Almost surely, 2^86186781 is an apocalyptic number.

It is an amenable number.

86186781 is a deficient number, since it is larger than the sum of its proper divisors (41773219).

86186781 is a wasteful number, since it uses less digits than its factorization.

86186781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6905 (or 6899 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 86186781 is about 9283.6835900412. The cubic root of 86186781 is about 441.7198203185.

The spelling of 86186781 in words is "eighty-six million, one hundred eighty-six thousand, seven hundred eighty-one".