81171383 has 4 divisors (see below), whose sum is σ = 81199008. Its totient is φ = 81143760.

The previous prime is 81171329. The next prime is 81171407. The reversal of 81171383 is 38317118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81171383 - 2⁸ = 81171127 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 (81171323) 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, 8798 + ... + 15483.

It is an arithmetic number, because the mean of its divisors is an integer number (20299752).

Almost surely, 2^81171383 is an apocalyptic number.

81171383 is a deficient number, since it is larger than the sum of its proper divisors (27625).

81171383 is a wasteful number, since it uses less digits than its factorization.

81171383 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27624.

The product of its digits is 4032, while the sum is 32.

The square root of 81171383 is about 9009.5162467249. The cubic root of 81171383 is about 432.9798129857.

The spelling of 81171383 in words is "eighty-one million, one hundred seventy-one thousand, three hundred eighty-three".