71239823 has 4 divisors (see below), whose sum is σ = 71256720. Its totient is φ = 71222928.

The previous prime is 71239789. The next prime is 71239853. The reversal of 71239823 is 32893217.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 71239823 - 2¹⁶ = 71174287 is a prime.

It is a super-2 number, since 2×71239823² = 10150224762142658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71239853) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3686 + ... + 12492.

It is an arithmetic number, because the mean of its divisors is an integer number (17814180).

Almost surely, 2^71239823 is an apocalyptic number.

71239823 is a deficient number, since it is larger than the sum of its proper divisors (16897).

71239823 is an equidigital number, since it uses as much as digits as its factorization.

71239823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16896.

The product of its digits is 18144, while the sum is 35.

The square root of 71239823 is about 8440.3686530862. The cubic root of 71239823 is about 414.5474779044.

The spelling of 71239823 in words is "seventy-one million, two hundred thirty-nine thousand, eight hundred twenty-three".