81793928590 has 64 divisors (see below), whose sum is σ = 169159415040. Its totient is φ = 28162391040.

The previous prime is 81793928561. The next prime is 81793928617. The reversal of 81793928590 is 9582939718.

It is a congruent number.

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, 4205829 + ... + 4225231.

It is an arithmetic number, because the mean of its divisors is an integer number (2643115860).

Almost surely, 2^81793928590 is an apocalyptic number.

81793928590 is an abundant number, since it is smaller than the sum of its proper divisors (87365486450).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81793928590 is a wasteful number, since it uses less digits than its factorization.

81793928590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21457.

The product of its (nonzero) digits is 9797760, while the sum is 61.

The spelling of 81793928590 in words is "eighty-one billion, seven hundred ninety-three million, nine hundred twenty-eight thousand, five hundred ninety".