81788200705878 has 16 divisors (see below), whose sum is σ = 167566069739376. Its totient is φ = 26597788847360.

The previous prime is 81788200705867. The next prime is 81788200705931. The reversal of 81788200705878 is 87850700288718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166236180051 + ... + 166236180542.

It is an arithmetic number, because the mean of its divisors is an integer number (10472879358711).

Almost surely, 2^{81788200705878} is an apocalyptic number.

81788200705878 is an abundant number, since it is smaller than the sum of its proper divisors (85777869033498).

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

81788200705878 is a wasteful number, since it uses less digits than its factorization.

81788200705878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332472360639.

The product of its (nonzero) digits is 112394240, while the sum is 69.

The spelling of 81788200705878 in words is "eighty-one trillion, seven hundred eighty-eight billion, two hundred million, seven hundred five thousand, eight hundred seventy-eight".