81854093840 has 80 divisors (see below), whose sum is σ = 203224135680. Its totient is φ = 30592826880.

The previous prime is 81854093813. The next prime is 81854093921. The reversal of 81854093840 is 4839045818.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 497144 + ... + 640983.

It is an arithmetic number, because the mean of its divisors is an integer number (2540301696).

Almost surely, 2^81854093840 is an apocalyptic number.

81854093840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81854093840 is an abundant number, since it is smaller than the sum of its proper divisors (121370041840).

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

81854093840 is a wasteful number, since it uses less digits than its factorization.

81854093840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138200 (or 1138194 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 50.

The spelling of 81854093840 in words is "eighty-one billion, eight hundred fifty-four million, ninety-three thousand, eight hundred forty".