81848071440 has 60 divisors (see below), whose sum is σ = 274873109004. Its totient is φ = 21826152192.

The previous prime is 81848071421. The next prime is 81848071441. The reversal of 81848071440 is 4417084818.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 62132541696 + 19715529744 = 249264^2 + 140412^2 .

It is a tau number, because it is divible by the number of its divisors (60).

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

It is not an unprimeable number, because it can be changed into a prime (81848071441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56838219 + ... + 56839658.

Almost surely, 2^81848071440 is an apocalyptic number.

81848071440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81848071440 is an abundant number, since it is smaller than the sum of its proper divisors (193025037564).

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

81848071440 is a wasteful number, since it uses less digits than its factorization.

81848071440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113677896 (or 113677887 counting only the distinct ones).

The product of its (nonzero) digits is 229376, while the sum is 45.

The spelling of 81848071440 in words is "eighty-one billion, eight hundred forty-eight million, seventy-one thousand, four hundred forty".