81731174545 has 16 divisors (see below), whose sum is σ = 98322416640. Its totient is φ = 65221700544.

The previous prime is 81731174477. The next prime is 81731174561. The reversal of 81731174545 is 54547113718.

It is a cyclic number.

It is not a de Polignac number, because 81731174545 - 2⁹ = 81731174033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81731174495 and 81731174504.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12773287 + ... + 12779683.

It is an arithmetic number, because the mean of its divisors is an integer number (6145151040).

Almost surely, 2^81731174545 is an apocalyptic number.

It is an amenable number.

81731174545 is a deficient number, since it is larger than the sum of its proper divisors (16591242095).

81731174545 is a wasteful number, since it uses less digits than its factorization.

81731174545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12384.

The product of its digits is 470400, while the sum is 46.

The spelling of 81731174545 in words is "eighty-one billion, seven hundred thirty-one million, one hundred seventy-four thousand, five hundred forty-five".