81845844 has 24 divisors (see below), whose sum is σ = 201025440. Its totient is φ = 25845984.

The previous prime is 81845831. The next prime is 81845851. The reversal of 81845844 is 44854818.

It is a junction number, because it is equal to n+sod(n) for n = 81845796 and 81845805.

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, 179259 + ... + 179714.

It is an arithmetic number, because the mean of its divisors is an integer number (8376060).

Almost surely, 2^81845844 is an apocalyptic number.

It is an amenable number.

81845844 is an abundant number, since it is smaller than the sum of its proper divisors (119179596).

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

81845844 is a wasteful number, since it uses less digits than its factorization.

81845844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358999 (or 358997 counting only the distinct ones).

The product of its digits is 163840, while the sum is 42.

The square root of 81845844 is about 9046.8692927443. The cubic root of 81845844 is about 434.1757306858.

It can be divided in two parts, 8184 and 5844, that added together give a triangular number (14028 = T₁₆₇).

The spelling of 81845844 in words is "eighty-one million, eight hundred forty-five thousand, eight hundred forty-four".