81275412905 has 32 divisors (see below), whose sum is σ = 102632140800. Its totient is φ = 61703695872.

The previous prime is 81275412899. The next prime is 81275412923. The reversal of 81275412905 is 50921457218.

It is a cyclic number.

It is not a de Polignac number, because 81275412905 - 2³² = 76980445609 is a prime.

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 31 ways as a sum of consecutive naturals, for example, 2538557 + ... + 2570373.

It is an arithmetic number, because the mean of its divisors is an integer number (3207254400).

Almost surely, 2^81275412905 is an apocalyptic number.

It is an amenable number.

81275412905 is a deficient number, since it is larger than the sum of its proper divisors (21356727895).

81275412905 is a wasteful number, since it uses less digits than its factorization.

81275412905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32153.

The product of its (nonzero) digits is 201600, while the sum is 44.

The spelling of 81275412905 in words is "eighty-one billion, two hundred seventy-five million, four hundred twelve thousand, nine hundred five".