81485760 has 112 divisors (see below), whose sum is σ = 273990816. Its totient is φ = 20447232.

The previous prime is 81485759. The next prime is 81485771. The reversal of 81485760 is 6758418.

It is a congruent number.

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, 13824 + ... + 18816.

Almost surely, 2^81485760 is an apocalyptic number.

81485760 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81485760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136995408).

81485760 is an abundant number, since it is smaller than the sum of its proper divisors (192505056).

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

81485760 is a wasteful number, since it uses less digits than its factorization.

81485760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5030 (or 5020 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 39.

The square root of 81485760 is about 9026.9463275241. The cubic root of 81485760 is about 433.5380702482.

The spelling of 81485760 in words is "eighty-one million, four hundred eighty-five thousand, seven hundred sixty".