81387648 has 192 divisors, whose sum is σ = 252046080. Its totient is φ = 25159680.

The previous prime is 81387643. The next prime is 81387667. The reversal of 81387648 is 84678318.

It is a tau number, because it is divible by the number of its divisors (192).

It is not an unprimeable number, because it can be changed into a prime (81387643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1535590 + ... + 1535642.

It is an arithmetic number, because the mean of its divisors is an integer number (1312740).

Almost surely, 2^81387648 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 81387648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126023040).

81387648 is an abundant number, since it is smaller than the sum of its proper divisors (170658432).

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

81387648 is a wasteful number, since it uses less digits than its factorization.

81387648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 132 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 81387648 is about 9021.5102948453. The cubic root of 81387648 is about 433.3640015113.

The spelling of 81387648 in words is "eighty-one million, three hundred eighty-seven thousand, six hundred forty-eight".