81630782844 has 48 divisors (see below), whose sum is σ = 206430086688. Its totient is φ = 24957174528.

The previous prime is 81630782819. The next prime is 81630782921. The reversal of 81630782844 is 44828703618.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1641987 + ... + 1690970.

It is an arithmetic number, because the mean of its divisors is an integer number (4300626806).

Almost surely, 2^81630782844 is an apocalyptic number.

It is an amenable number.

81630782844 is an abundant number, since it is smaller than the sum of its proper divisors (124799303844).

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

81630782844 is a wasteful number, since it uses less digits than its factorization.

81630782844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3333134 (or 3333132 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 51.

The spelling of 81630782844 in words is "eighty-one billion, six hundred thirty million, seven hundred eighty-two thousand, eight hundred forty-four".