81441315840 has 88 divisors (see below), whose sum is σ = 260485007760. Its totient is φ = 21717680128.

The previous prime is 81441315803. The next prime is 81441315841. The reversal of 81441315840 is 4851314418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81441315841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2635725 + ... + 2666444.

Almost surely, 2^81441315840 is an apocalyptic number.

81441315840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81441315840 is an abundant number, since it is smaller than the sum of its proper divisors (179043691920).

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

81441315840 is a wasteful number, since it uses less digits than its factorization.

81441315840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5302197 (or 5302179 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 39.

The spelling of 81441315840 in words is "eighty-one billion, four hundred forty-one million, three hundred fifteen thousand, eight hundred forty".