81547805745 has 48 divisors (see below), whose sum is σ = 162254102400. Its totient is φ = 37114739712.

The previous prime is 81547805719. The next prime is 81547805753. The reversal of 81547805745 is 54750874518.

81547805745 is a `hidden beast` number, since 8 + 1 + 547 + 8 + 0 + 57 + 45 = 666.

It is not a de Polignac number, because 81547805745 - 2¹⁷ = 81547674673 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81547805691 and 81547805700.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 498720 + ... + 641729.

It is an arithmetic number, because the mean of its divisors is an integer number (3380293800).

Almost surely, 2^81547805745 is an apocalyptic number.

It is an amenable number.

81547805745 is a deficient number, since it is larger than the sum of its proper divisors (80706296655).

81547805745 is a wasteful number, since it uses less digits than its factorization.

81547805745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140694 (or 1140691 counting only the distinct ones).

The product of its (nonzero) digits is 6272000, while the sum is 54.

The spelling of 81547805745 in words is "eighty-one billion, five hundred forty-seven million, eight hundred five thousand, seven hundred forty-five".