81682905545 has 16 divisors (see below), whose sum is σ = 98149647888. Its totient is φ = 65259617280.

The previous prime is 81682905527. The next prime is 81682905559. The reversal of 81682905545 is 54550928618.

It can be written as a sum of positive squares in 8 ways, for example, as 181791289 + 81501114256 = 13483^2 + 285484^2 .

It is not a de Polignac number, because 81682905545 - 2²⁸ = 81414470089 is a prime.

It is a Duffinian number.

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 15 ways as a sum of consecutive naturals, for example, 21510587 + ... + 21514383.

It is an arithmetic number, because the mean of its divisors is an integer number (6134352993).

Almost surely, 2^81682905545 is an apocalyptic number.

It is an amenable number.

81682905545 is a deficient number, since it is larger than the sum of its proper divisors (16466742343).

81682905545 is a wasteful number, since it uses less digits than its factorization.

81682905545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8380.

The product of its (nonzero) digits is 3456000, while the sum is 53.

The spelling of 81682905545 in words is "eighty-one billion, six hundred eighty-two million, nine hundred five thousand, five hundred forty-five".