81634684040 has 192 divisors, whose sum is σ = 233541403200. Its totient is φ = 25449887232.

The previous prime is 81634683983. The next prime is 81634684051. The reversal of 81634684040 is 4048643618.

It is a junction number, because it is equal to n+sod(n) for n = 81634683982 and 81634684000.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1683251 + ... + 1731069.

It is an arithmetic number, because the mean of its divisors is an integer number (1216361475).

Almost surely, 2^81634684040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81634684040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116770701600).

81634684040 is an abundant number, since it is smaller than the sum of its proper divisors (151906719160).

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

81634684040 is a wasteful number, since it uses less digits than its factorization.

81634684040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47924 (or 47913 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 44.

The spelling of 81634684040 in words is "eighty-one billion, six hundred thirty-four million, six hundred eighty-four thousand, forty".