81240448 has 32 divisors (see below), whose sum is σ = 164279160. Its totient is φ = 40009728.

The previous prime is 81240431. The next prime is 81240451. The reversal of 81240448 is 84404218.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 3840 + ... + 13312.

Almost surely, 2^81240448 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 81240448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82139580).

81240448 is an abundant number, since it is smaller than the sum of its proper divisors (83038712).

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

81240448 is an equidigital number, since it uses as much as digits as its factorization.

81240448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9554 (or 9542 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 31.

The square root of 81240448 is about 9013.3483234589. The cubic root of 81240448 is about 433.1025790495.

The spelling of 81240448 in words is "eighty-one million, two hundred forty thousand, four hundred forty-eight".