81447104745 has 32 divisors (see below), whose sum is σ = 148162185600. Its totient is φ = 42428256192.

The previous prime is 81447104723. The next prime is 81447104803. The reversal of 81447104745 is 54740174418.

It is not a de Polignac number, because 81447104745 - 2¹⁶ = 81447039209 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81447104745.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 7009450 + ... + 7021059.

It is an arithmetic number, because the mean of its divisors is an integer number (4630068300).

Almost surely, 2^81447104745 is an apocalyptic number.

It is an amenable number.

81447104745 is a deficient number, since it is larger than the sum of its proper divisors (66715080855).

81447104745 is a wasteful number, since it uses less digits than its factorization.

81447104745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14030566 (or 14030560 counting only the distinct ones).

The product of its (nonzero) digits is 501760, while the sum is 45.

It can be divided in two parts, 8144 and 7104745, that added together give a square (7112889 = 2667²).

The spelling of 81447104745 in words is "eighty-one billion, four hundred forty-seven million, one hundred four thousand, seven hundred forty-five".