81180066240 has 1120 divisors, whose sum is σ = 359531741184. Its totient is φ = 16930529280.

The previous prime is 81180066179. The next prime is 81180066259. The reversal of 81180066240 is 4266008118.

It is a tau number, because it is divible by the number of its divisors (1120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 81180066195 and 81180066204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 299557305 + ... + 299557575.

Almost surely, 2^81180066240 is an apocalyptic number.

81180066240 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 81180066240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (179765870592).

81180066240 is an abundant number, since it is smaller than the sum of its proper divisors (278351674944).

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

81180066240 is a wasteful number, since it uses less digits than its factorization.

81180066240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 81180066240 in words is "eighty-one billion, one hundred eighty million, sixty-six thousand, two hundred forty".