81730485538 has 32 divisors (see below), whose sum is σ = 142206926400. Its totient is φ = 34905318336.

The previous prime is 81730485511. The next prime is 81730485569. The reversal of 81730485538 is 83558403718.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1902553 + ... + 1945036.

It is an arithmetic number, because the mean of its divisors is an integer number (4443966450).

Almost surely, 2^81730485538 is an apocalyptic number.

81730485538 is a deficient number, since it is larger than the sum of its proper divisors (60476440862).

81730485538 is a wasteful number, since it uses less digits than its factorization.

81730485538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3847666.

The product of its (nonzero) digits is 3225600, while the sum is 52.

The spelling of 81730485538 in words is "eighty-one billion, seven hundred thirty million, four hundred eighty-five thousand, five hundred thirty-eight".