81539827005 has 32 divisors (see below), whose sum is σ = 160570738944. Its totient is φ = 34408014336.

The previous prime is 81539827001. The next prime is 81539827007. The reversal of 81539827005 is 50072893518.

It is not a de Polignac number, because 81539827005 - 2² = 81539827001 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81539827001) 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, 29866704 + ... + 29869433.

It is an arithmetic number, because the mean of its divisors is an integer number (5017835592).

Almost surely, 2^81539827005 is an apocalyptic number.

It is an amenable number.

81539827005 is a deficient number, since it is larger than the sum of its proper divisors (79030911939).

81539827005 is a wasteful number, since it uses less digits than its factorization.

81539827005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59736165.

The product of its (nonzero) digits is 604800, while the sum is 48.

The spelling of 81539827005 in words is "eighty-one billion, five hundred thirty-nine million, eight hundred twenty-seven thousand, five".