81367193 has 4 divisors (see below), whose sum is σ = 81387108. Its totient is φ = 81347280.

The previous prime is 81367163. The next prime is 81367211. The reversal of 81367193 is 39176318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 39176318 = 2 ⋅19588159.

It can be written as a sum of positive squares in 2 ways, for example, as 57032704 + 24334489 = 7552^2 + 4933^2 .

It is a cyclic number.

It is not a de Polignac number, because 81367193 - 2¹⁰ = 81366169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81367103) 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, 1346 + ... + 12827.

It is an arithmetic number, because the mean of its divisors is an integer number (20346777).

Almost surely, 2^81367193 is an apocalyptic number.

It is an amenable number.

81367193 is a deficient number, since it is larger than the sum of its proper divisors (19915).

81367193 is a wasteful number, since it uses less digits than its factorization.

81367193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19914.

The product of its digits is 27216, while the sum is 38.

The square root of 81367193 is about 9020.3765442469. The cubic root of 81367193 is about 433.3276929575.

The spelling of 81367193 in words is "eighty-one million, three hundred sixty-seven thousand, one hundred ninety-three".