81308448 has 240 divisors, whose sum is σ = 273208320. Its totient is φ = 23514624.

The previous prime is 81308411. The next prime is 81308477. The reversal of 81308448 is 84480318.

It is a super-2 number, since 2×81308448² = 13222127432337408, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 640161 + ... + 640287.

It is an arithmetic number, because the mean of its divisors is an integer number (1138368).

Almost surely, 2^81308448 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 81308448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136604160).

81308448 is an abundant number, since it is smaller than the sum of its proper divisors (191899872).

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

81308448 is a wasteful number, since it uses less digits than its factorization.

81308448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 81308448 is about 9017.1197175151. The cubic root of 81308448 is about 433.2233840708.

The spelling of 81308448 in words is "eighty-one million, three hundred eight thousand, four hundred forty-eight".