81835040 has 96 divisors (see below), whose sum is σ = 228178944. Its totient is φ = 27141120.

The previous prime is 81835031. The next prime is 81835043. The reversal of 81835040 is 4053818.

It is a junction number, because it is equal to n+sod(n) for n = 81834994 and 81835012.

It is not an unprimeable number, because it can be changed into a prime (81835043) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33542 + ... + 35898.

It is an arithmetic number, because the mean of its divisors is an integer number (2376864).

Almost surely, 2^81835040 is an apocalyptic number.

81835040 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81835040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114089472).

81835040 is an abundant number, since it is smaller than the sum of its proper divisors (146343904).

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

81835040 is a wasteful number, since it uses less digits than its factorization.

81835040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2410 (or 2402 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 81835040 is about 9046.2721603984. The cubic root of 81835040 is about 434.1566254966.

Adding to 81835040 its reverse (4053818), we get a palindrome (85888858).

The spelling of 81835040 in words is "eighty-one million, eight hundred thirty-five thousand, forty".