81877183744 has 18 divisors (see below), whose sum is σ = 163434535250. Its totient is φ = 40938591744.

The previous prime is 81877183697. The next prime is 81877183747. The reversal of 81877183744 is 44738177818.

It can be written as a sum of positive squares in only one way, i.e., 50844838144 + 31032345600 = 225488^2 + 176160^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81877183747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159916119 + ... + 159916630.

Almost surely, 2^81877183744 is an apocalyptic number.

It is an amenable number.

81877183744 is a deficient number, since it is larger than the sum of its proper divisors (81557351506).

81877183744 is an equidigital number, since it uses as much as digits as its factorization.

81877183744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319832765 (or 319832751 counting only the distinct ones).

The product of its digits is 8429568, while the sum is 58.

The spelling of 81877183744 in words is "eighty-one billion, eight hundred seventy-seven million, one hundred eighty-three thousand, seven hundred forty-four".