81447443512 has 32 divisors (see below), whose sum is σ = 155790475200. Its totient is φ = 39908246400.

The previous prime is 81447443443. The next prime is 81447443521. The reversal of 81447443512 is 21534474418.

It is a congruent 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 7 ways as a sum of consecutive naturals, for example, 175687 + ... + 440182.

It is an arithmetic number, because the mean of its divisors is an integer number (4868452350).

Almost surely, 2^81447443512 is an apocalyptic number.

It is an amenable number.

81447443512 is a deficient number, since it is larger than the sum of its proper divisors (74343031688).

81447443512 is a wasteful number, since it uses less digits than its factorization.

81447443512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616207 (or 616203 counting only the distinct ones).

The product of its digits is 430080, while the sum is 43.

The spelling of 81447443512 in words is "eighty-one billion, four hundred forty-seven million, four hundred forty-three thousand, five hundred twelve".