81857468 has 72 divisors (see below), whose sum is σ = 185097696. Its totient is φ = 30983040.

The previous prime is 81857417. The next prime is 81857473. The reversal of 81857468 is 86475818.

It is a happy number.

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 23 ways as a sum of consecutive naturals, for example, 125030 + ... + 125682.

Almost surely, 2^81857468 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81857468, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92548848).

81857468 is an abundant number, since it is smaller than the sum of its proper divisors (103240228).

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

81857468 is a wasteful number, since it uses less digits than its factorization.

81857468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723 (or 710 counting only the distinct ones).

The product of its digits is 430080, while the sum is 47.

The square root of 81857468 is about 9047.5117021201. The cubic root of 81857468 is about 434.1962840397.

The spelling of 81857468 in words is "eighty-one million, eight hundred fifty-seven thousand, four hundred sixty-eight".