81823331 has 4 divisors (see below), whose sum is σ = 83819064. Its totient is φ = 79827600.

The previous prime is 81823327. The next prime is 81823333. The reversal of 81823331 is 13332818.

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 81823331 - 2² = 81823327 is a prime.

It is a super-2 number, since 2×81823331² = 13390114991871122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81823294 and 81823303.

It is not an unprimeable number, because it can be changed into a prime (81823333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 997805 + ... + 997886.

It is an arithmetic number, because the mean of its divisors is an integer number (20954766).

Almost surely, 2^81823331 is an apocalyptic number.

81823331 is a deficient number, since it is larger than the sum of its proper divisors (1995733).

81823331 is a wasteful number, since it uses less digits than its factorization.

81823331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995732.

The product of its digits is 3456, while the sum is 29.

The square root of 81823331 is about 9045.6249645892. The cubic root of 81823331 is about 434.1359180571.

The spelling of 81823331 in words is "eighty-one million, eight hundred twenty-three thousand, three hundred thirty-one".