81348191 has 4 divisors (see below), whose sum is σ = 81688800. Its totient is φ = 81007584.

The previous prime is 81348167. The next prime is 81348193. The reversal of 81348191 is 19184318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19184318 = 2 ⋅9592159.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81348191 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 (81348193) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169946 + ... + 170423.

It is an arithmetic number, because the mean of its divisors is an integer number (20422200).

Almost surely, 2^81348191 is an apocalyptic number.

81348191 is a deficient number, since it is larger than the sum of its proper divisors (340609).

81348191 is a wasteful number, since it uses less digits than its factorization.

81348191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340608.

The product of its digits is 6912, while the sum is 35.

The square root of 81348191 is about 9019.3232007729. The cubic root of 81348191 is about 433.2939580922.

The spelling of 81348191 in words is "eighty-one million, three hundred forty-eight thousand, one hundred ninety-one".