81000916133280 has 768 divisors, whose sum is σ = 304768965795840. Its totient is φ = 17825034240000.

The previous prime is 81000916133219. The next prime is 81000916133323. The reversal of 81000916133280 is 8233161900018.

It is a super-2 number, since 2×81000916133280² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1361032804 + ... + 1361092316.

It is an arithmetic number, because the mean of its divisors is an integer number (396834590880).

Almost surely, 2^{81000916133280} is an apocalyptic number.

81000916133280 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 81000916133280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152384482897920).

81000916133280 is an abundant number, since it is smaller than the sum of its proper divisors (223768049662560).

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

81000916133280 is a wasteful number, since it uses less digits than its factorization.

81000916133280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59885 (or 59877 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 42.

The spelling of 81000916133280 in words is "eighty-one trillion, nine hundred sixteen million, one hundred thirty-three thousand, two hundred eighty".