86138809 has 2 divisors, whose sum is σ = 86138810. Its totient is φ = 86138808.

The previous prime is 86138807. The next prime is 86138821. The reversal of 86138809 is 90883168.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70560000 + 15578809 = 8400^2 + 3947^2 .

It is a cyclic number.

It is not a de Polignac number, because 86138809 - 2¹ = 86138807 is a prime.

Together with 86138807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (86138803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43069404 + 43069405.

It is an arithmetic number, because the mean of its divisors is an integer number (43069405).

Almost surely, 2^86138809 is an apocalyptic number.

It is an amenable number.

86138809 is a deficient number, since it is larger than the sum of its proper divisors (1).

86138809 is an equidigital number, since it uses as much as digits as its factorization.

86138809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 86138809 is about 9281.0995577033. The cubic root of 86138809 is about 441.6378506100.

The spelling of 86138809 in words is "eighty-six million, one hundred thirty-eight thousand, eight hundred nine".