81788884767 has 24 divisors (see below), whose sum is σ = 118975278240. Its totient is φ = 54140886720.

The previous prime is 81788884757. The next prime is 81788884799. The reversal of 81788884767 is 76748888718.

81788884767 is a `hidden beast` number, since 8 + 1 + 78 + 8 + 88 + 476 + 7 = 666.

It is not a de Polignac number, because 81788884767 - 2²³ = 81780496159 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81788884695 and 81788884704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81788884757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1385409 + ... + 1443237.

It is an arithmetic number, because the mean of its divisors is an integer number (4957303260).

Almost surely, 2^81788884767 is an apocalyptic number.

81788884767 is a deficient number, since it is larger than the sum of its proper divisors (37186393473).

81788884767 is a wasteful number, since it uses less digits than its factorization.

81788884767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58943 (or 58940 counting only the distinct ones).

The product of its digits is 269746176, while the sum is 72.

The spelling of 81788884767 in words is "eighty-one billion, seven hundred eighty-eight million, eight hundred eighty-four thousand, seven hundred sixty-seven".