81121167912960 has 3640 divisors, whose sum is σ = 356289599627904. Its totient is φ = 17698046607360.

The previous prime is 81121167912877. The next prime is 81121167912977. The reversal of 81121167912960 is 6921976112118.

81121167912960 is a `hidden beast` number, since 81 + 1 + 211 + 67 + 9 + 1 + 296 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 81121167912897 and 81121167912906.

It is an unprimeable number.

It is a polite number, since it can be written in 279 ways as a sum of consecutive naturals, for example, 1111248875484 + ... + 1111248875556.

Almost surely, 2^{81121167912960} is an apocalyptic number.

81121167912960 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 81121167912960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (178144799813952).

81121167912960 is an abundant number, since it is smaller than the sum of its proper divisors (275168431714944).

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

81121167912960 is an frugal number, since it uses more digits than its factorization.

81121167912960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 54.

The spelling of 81121167912960 in words is "eighty-one trillion, one hundred twenty-one billion, one hundred sixty-seven million, nine hundred twelve thousand, nine hundred sixty".