81967385 has 8 divisors (see below), whose sum is σ = 98528136. Its totient is φ = 65462400.

The previous prime is 81967351. The next prime is 81967439. The reversal of 81967385 is 58376918.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 9853321 + 72114064 = 3139^2 + 8492^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81967385 - 2⁸ = 81967129 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 10634 + ... + 16643.

It is an arithmetic number, because the mean of its divisors is an integer number (12316017).

Almost surely, 2^81967385 is an apocalyptic number.

It is an amenable number.

81967385 is a deficient number, since it is larger than the sum of its proper divisors (16560751).

81967385 is a wasteful number, since it uses less digits than its factorization.

81967385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27883.

The product of its digits is 362880, while the sum is 47.

The square root of 81967385 is about 9053.5840969198. The cubic root of 81967385 is about 434.3905412379.

The spelling of 81967385 in words is "eighty-one million, nine hundred sixty-seven thousand, three hundred eighty-five".