81854910 has 48 divisors (see below), whose sum is σ = 214053840. Its totient is φ = 21701760.

The previous prime is 81854909. The next prime is 81854921. The reversal of 81854910 is 1945818.

It is a super-2 number, since 2×81854910² = 13400452582216200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13570 + ... + 18650.

It is an arithmetic number, because the mean of its divisors is an integer number (4459455).

Almost surely, 2^81854910 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81854910, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107026920).

81854910 is an abundant number, since it is smaller than the sum of its proper divisors (132198930).

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

81854910 is a wasteful number, since it uses less digits than its factorization.

81854910 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5273 (or 5270 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 81854910 is about 9047.3703361806. The cubic root of 81854910 is about 434.1917611957.

The spelling of 81854910 in words is "eighty-one million, eight hundred fifty-four thousand, nine hundred ten".