81119831 has 8 divisors (see below), whose sum is σ = 87879120. Its totient is φ = 74877816.

The previous prime is 81119821. The next prime is 81119849. The reversal of 81119831 is 13891118.

It is a de Polignac number, because none of the positive numbers 2^k-81119831 is a prime.

It is a super-2 number, since 2×81119831² = 13160853962937122, 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 (81119821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16265 + ... + 20658.

It is an arithmetic number, because the mean of its divisors is an integer number (10984890).

Almost surely, 2^81119831 is an apocalyptic number.

81119831 is a deficient number, since it is larger than the sum of its proper divisors (6759289).

81119831 is an equidigital number, since it uses as much as digits as its factorization.

81119831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36962 (or 36936 counting only the distinct ones).

The product of its digits is 1728, while the sum is 32.

The square root of 81119831 is about 9006.6548174114. The cubic root of 81119831 is about 432.8881316504. Note that the first 3 decimals are identical.

The spelling of 81119831 in words is "eighty-one million, one hundred nineteen thousand, eight hundred thirty-one".