81148519440 has 320 divisors, whose sum is σ = 298300907520. Its totient is φ = 20205158400.

The previous prime is 81148519427. The next prime is 81148519451. The reversal of 81148519440 is 4491584118.

81148519440 is a `hidden beast` number, since 8 + 114 + 85 + 19 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4654740 + ... + 4672140.

It is an arithmetic number, because the mean of its divisors is an integer number (932190336).

Almost surely, 2^81148519440 is an apocalyptic number.

81148519440 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 81148519440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149150453760).

81148519440 is an abundant number, since it is smaller than the sum of its proper divisors (217152388080).

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

81148519440 is a wasteful number, since it uses less digits than its factorization.

81148519440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17567 (or 17555 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 45.

The spelling of 81148519440 in words is "eighty-one billion, one hundred forty-eight million, five hundred nineteen thousand, four hundred forty".