81705990600 has 768 divisors, whose sum is σ = 312355008000. Its totient is φ = 19624550400.

The previous prime is 81705990593. The next prime is 81705990649. The reversal of 81705990600 is 609950718.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 842329752 + ... + 842329848.

It is an arithmetic number, because the mean of its divisors is an integer number (406712250).

Almost surely, 2^81705990600 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 81705990600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156177504000).

81705990600 is an abundant number, since it is smaller than the sum of its proper divisors (230649017400).

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

81705990600 is a wasteful number, since it uses less digits than its factorization.

81705990600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The spelling of 81705990600 in words is "eighty-one billion, seven hundred five million, nine hundred ninety thousand, six hundred".