81833840 has 40 divisors (see below), whose sum is σ = 207562608. Its totient is φ = 29757440.

The previous prime is 81833813. The next prime is 81833863. The reversal of 81833840 is 4833818.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 81833840.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 45617 + ... + 47376.

Almost surely, 2^81833840 is an apocalyptic number.

81833840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81833840 is an abundant number, since it is smaller than the sum of its proper divisors (125728768).

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

81833840 is a wasteful number, since it uses less digits than its factorization.

81833840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93017 (or 93011 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 81833840 is about 9046.2058344922. The cubic root of 81833840 is about 434.1545033799.

The spelling of 81833840 in words is "eighty-one million, eight hundred thirty-three thousand, eight hundred forty".