81831787008 has 40 divisors (see below), whose sum is σ = 218004999168. Its totient is φ = 27277261824.

The previous prime is 81831786979. The next prime is 81831787031. The reversal of 81831787008 is 80078713818.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26636416 + ... + 26639487.

Almost surely, 2^81831787008 is an apocalyptic number.

It is an amenable number.

81831787008 is an abundant number, since it is smaller than the sum of its proper divisors (136173212160).

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

81831787008 is an equidigital number, since it uses as much as digits as its factorization.

81831787008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53275924 (or 53275908 counting only the distinct ones).

The product of its (nonzero) digits is 602112, while the sum is 51.

The spelling of 81831787008 in words is "eighty-one billion, eight hundred thirty-one million, seven hundred eighty-seven thousand, eight".