81212582880 has 864 divisors, whose sum is σ = 338719032288. Its totient is φ = 18139852800.

The previous prime is 81212582861. The next prime is 81212582947. The reversal of 81212582880 is 8828521218.

It is a tau number, because it is divible by the number of its divisors (864).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 150115410 + ... + 150115950.

It is an arithmetic number, because the mean of its divisors is an integer number (392035917).

Almost surely, 2^81212582880 is an apocalyptic number.

81212582880 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81212582880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169359516144).

81212582880 is an abundant number, since it is smaller than the sum of its proper divisors (257506449408).

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

81212582880 is a wasteful number, since it uses less digits than its factorization.

81212582880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604 (or 575 counting only the distinct ones).

The product of its (nonzero) digits is 163840, while the sum is 45.

The spelling of 81212582880 in words is "eighty-one billion, two hundred twelve million, five hundred eighty-two thousand, eight hundred eighty".