81378648 has 128 divisors (see below), whose sum is σ = 247396800. Its totient is φ = 24634368.

The previous prime is 81378613. The next prime is 81378673. The reversal of 81378648 is 84687318.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 204786 + ... + 205182.

Almost surely, 2^81378648 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 81378648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123698400).

81378648 is an abundant number, since it is smaller than the sum of its proper divisors (166018152).

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

81378648 is a wasteful number, since it uses less digits than its factorization.

81378648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498 (or 488 counting only the distinct ones).

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

The square root of 81378648 is about 9021.0114732218. The cubic root of 81378648 is about 433.3480268522.

The spelling of 81378648 in words is "eighty-one million, three hundred seventy-eight thousand, six hundred forty-eight".