81457712 has 80 divisors (see below), whose sum is σ = 192249600. Its totient is φ = 32659200.

The previous prime is 81457711. The next prime is 81457799. The reversal of 81457712 is 21775418.

It is not an unprimeable number, because it can be changed into a prime (81457711) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 214739 + ... + 215117.

It is an arithmetic number, because the mean of its divisors is an integer number (2403120).

Almost surely, 2^81457712 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 81457712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96124800).

81457712 is an abundant number, since it is smaller than the sum of its proper divisors (110791888).

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

81457712 is a wasteful number, since it uses less digits than its factorization.

81457712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514 (or 508 counting only the distinct ones).

The product of its digits is 15680, while the sum is 35.

The square root of 81457712 is about 9025.3926230386. The cubic root of 81457712 is about 433.4883222053.

The spelling of 81457712 in words is "eighty-one million, four hundred fifty-seven thousand, seven hundred twelve".