81313944456 has 16 divisors (see below), whose sum is σ = 203284861200. Its totient is φ = 27104648144.

The previous prime is 81313944407. The next prime is 81313944457. The reversal of 81313944456 is 65444931318.

It is a super-2 number, since 2×81313944456² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81313944457) 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 3 ways as a sum of consecutive naturals, for example, 1694040486 + ... + 1694040533.

It is an arithmetic number, because the mean of its divisors is an integer number (12705303825).

Almost surely, 2^81313944456 is an apocalyptic number.

It is an amenable number.

81313944456 is an abundant number, since it is smaller than the sum of its proper divisors (121970916744).

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

81313944456 is a wasteful number, since it uses less digits than its factorization.

81313944456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3388081028 (or 3388081024 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 48.

The spelling of 81313944456 in words is "eighty-one billion, three hundred thirteen million, nine hundred forty-four thousand, four hundred fifty-six".