81669765070080 has 1728 divisors, whose sum is σ = 328947270462720. Its totient is φ = 18517524480000.

The previous prime is 81669765070031. The next prime is 81669765070087. The reversal of 81669765070080 is 8007056796618.

81669765070080 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×81669765070080² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81669765070087) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 34128609364 + ... + 34128611756.

It is an arithmetic number, because the mean of its divisors is an integer number (190363003740).

Almost surely, 2^{81669765070080} is an apocalyptic number.

81669765070080 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 81669765070080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164473635231360).

81669765070080 is an abundant number, since it is smaller than the sum of its proper divisors (247277505392640).

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

81669765070080 is a wasteful number, since it uses less digits than its factorization.

81669765070080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2748 (or 2731 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 63.

The spelling of 81669765070080 in words is "eighty-one trillion, six hundred sixty-nine billion, seven hundred sixty-five million, seventy thousand, eighty".