81750992538 has 16 divisors (see below), whose sum is σ = 173119749120. Its totient is φ = 25647370176.

The previous prime is 81750992513. The next prime is 81750992551. The reversal of 81750992538 is 83529905718.

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 7 ways as a sum of consecutive naturals, for example, 400740058 + ... + 400740261.

It is an arithmetic number, because the mean of its divisors is an integer number (10819984320).

Almost surely, 2^81750992538 is an apocalyptic number.

81750992538 is an abundant number, since it is smaller than the sum of its proper divisors (91368756582).

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

81750992538 is a wasteful number, since it uses less digits than its factorization.

81750992538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801480341.

The product of its (nonzero) digits is 5443200, while the sum is 57.

The spelling of 81750992538 in words is "eighty-one billion, seven hundred fifty million, nine hundred ninety-two thousand, five hundred thirty-eight".