81854175623 has 32 divisors (see below), whose sum is σ = 94649720832. Its totient is φ = 70056632800.

The previous prime is 81854175581. The next prime is 81854175643. The reversal of 81854175623 is 32657145818.

It is a de Polignac number, because none of the positive numbers 2^k-81854175623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81854175643) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 11618540 + ... + 11625582.

It is an arithmetic number, because the mean of its divisors is an integer number (2957803776).

Almost surely, 2^81854175623 is an apocalyptic number.

81854175623 is a deficient number, since it is larger than the sum of its proper divisors (12795545209).

81854175623 is a wasteful number, since it uses less digits than its factorization.

81854175623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7795.

The product of its digits is 1612800, while the sum is 50.

The spelling of 81854175623 in words is "eighty-one billion, eight hundred fifty-four million, one hundred seventy-five thousand, six hundred twenty-three".