81285307456 has 28 divisors (see below), whose sum is σ = 162266424768. Its totient is φ = 40399279232.

The previous prime is 81285307417. The next prime is 81285307487. The reversal of 81285307456 is 65470358218.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3791956 + ... + 3813331.

It is an arithmetic number, because the mean of its divisors is an integer number (5795229456).

Almost surely, 2^81285307456 is an apocalyptic number.

It is an amenable number.

81285307456 is a deficient number, since it is larger than the sum of its proper divisors (80981117312).

81285307456 is a wasteful number, since it uses less digits than its factorization.

81285307456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7605466 (or 7605456 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 49.

The spelling of 81285307456 in words is "eighty-one billion, two hundred eighty-five million, three hundred seven thousand, four hundred fifty-six".