81904986930743 has 4 divisors (see below), whose sum is σ = 81905030878968. Its totient is φ = 81904942982520.

The previous prime is 81904986930709. The next prime is 81904986930749. The reversal of 81904986930743 is 34703968940918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81904986930743 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81904986930749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19048796 + ... + 22949217.

It is an arithmetic number, because the mean of its divisors is an integer number (20476257719742).

Almost surely, 2^{81904986930743} is an apocalyptic number.

81904986930743 is a deficient number, since it is larger than the sum of its proper divisors (43948225).

81904986930743 is a wasteful number, since it uses less digits than its factorization.

81904986930743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43948224.

The product of its (nonzero) digits is 282175488, while the sum is 71.

The spelling of 81904986930743 in words is "eighty-one trillion, nine hundred four billion, nine hundred eighty-six million, nine hundred thirty thousand, seven hundred forty-three".