81461680819200 has 3168 divisors, whose sum is σ = 352040997934080. Its totient is φ = 18445683916800.

The previous prime is 81461680819187. The next prime is 81461680819201. The reversal of 81461680819200 is 291808616418.

It is a happy number.

81461680819200 is a `hidden beast` number, since 8 + 1 + 4 + 616 + 8 + 0 + 8 + 19 + 2 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3168).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (81461680819201) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 278026214254 + ... + 278026214546.

Almost surely, 2^{81461680819200} is an apocalyptic number.

81461680819200 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 81461680819200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (176020498967040).

81461680819200 is an abundant number, since it is smaller than the sum of its proper divisors (270579317114880).

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

81461680819200 is a wasteful number, since it uses less digits than its factorization.

81461680819200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605 (or 570 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 54.

The spelling of 81461680819200 in words is "eighty-one trillion, four hundred sixty-one billion, six hundred eighty million, eight hundred nineteen thousand, two hundred".