81527317825405 has 32 divisors (see below), whose sum is σ = 109047503180160. Its totient is φ = 58150272983040.

The previous prime is 81527317825399. The next prime is 81527317825543. The reversal of 81527317825405 is 50452871372518.

It is not a de Polignac number, because 81527317825405 - 2³¹ = 81525170341757 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81527317825405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20644845 + ... + 24274765.

It is an arithmetic number, because the mean of its divisors is an integer number (3407734474380).

Almost surely, 2^{81527317825405} is an apocalyptic number.

81527317825405 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81527317825405 is a deficient number, since it is larger than the sum of its proper divisors (27520185354755).

81527317825405 is a wasteful number, since it uses less digits than its factorization.

81527317825405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3643869.

The product of its (nonzero) digits is 18816000, while the sum is 58.

The spelling of 81527317825405 in words is "eighty-one trillion, five hundred twenty-seven billion, three hundred seventeen million, eight hundred twenty-five thousand, four hundred five".