81466204920 has 256 divisors, whose sum is σ = 255538022400. Its totient is φ = 20751790080.

The previous prime is 81466204909. The next prime is 81466204933. The reversal of 81466204920 is 2940266418.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 221978577 + ... + 221978943.

It is an arithmetic number, because the mean of its divisors is an integer number (998195400).

Almost surely, 2^81466204920 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 81466204920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127769011200).

81466204920 is an abundant number, since it is smaller than the sum of its proper divisors (174071817480).

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

81466204920 is a wasteful number, since it uses less digits than its factorization.

81466204920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918 (or 914 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The spelling of 81466204920 in words is "eighty-one billion, four hundred sixty-six million, two hundred four thousand, nine hundred twenty".