81748084751 has 4 divisors (see below), whose sum is σ = 81750162312. Its totient is φ = 81746007192.

The previous prime is 81748084727. The next prime is 81748084753. The reversal of 81748084751 is 15748084718.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15748084718 = 2 ⋅7874042359.

It is a cyclic number.

It is not a de Polignac number, because 81748084751 - 2¹⁰ = 81748083727 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81748084693 and 81748084702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81748084753) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 978596 + ... + 1058841.

It is an arithmetic number, because the mean of its divisors is an integer number (20437540578).

Almost surely, 2^81748084751 is an apocalyptic number.

81748084751 is a deficient number, since it is larger than the sum of its proper divisors (2077561).

81748084751 is a wasteful number, since it uses less digits than its factorization.

81748084751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2077560.

The product of its (nonzero) digits is 2007040, while the sum is 53.

The spelling of 81748084751 in words is "eighty-one billion, seven hundred forty-eight million, eighty-four thousand, seven hundred fifty-one".