81031896 has 96 divisors (see below), whose sum is σ = 242021520. Its totient is φ = 24288000.

The previous prime is 81031891. The next prime is 81031897. The reversal of 81031896 is 69813018.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81031896.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81031891) 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 23 ways as a sum of consecutive naturals, for example, 79486 + ... + 80498.

Almost surely, 2^81031896 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81031896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121010760).

81031896 is an abundant number, since it is smaller than the sum of its proper divisors (160989624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81031896 is a wasteful number, since it uses less digits than its factorization.

81031896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1137 (or 1130 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 81031896 is about 9001.7718255908. The cubic root of 81031896 is about 432.7316562224.

It can be divided in two parts, 8103 and 1896, that added together give a palindrome (9999).

The spelling of 81031896 in words is "eighty-one million, thirty-one thousand, eight hundred ninety-six".