8121605128704 has 440 divisors, whose sum is σ = 24441914564892. Its totient is φ = 2695985233920.

The previous prime is 8121605128661. The next prime is 8121605128717. The reversal of 8121605128704 is 4078215061218.

8121605128704 is a `hidden beast` number, since 8 + 1 + 2 + 1 + 60 + 512 + 8 + 70 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6806087887104 + 1315517241600 = 2608848^2 + 1146960^2 .

It is a super-2 number, since 2×8121605128704² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 8121605128704.

It is an unprimeable number.

It is a polite number, since it can be written in 43 ways as a sum of consecutive naturals, for example, 10672279684 + ... + 10672280444.

Almost surely, 2^{8121605128704} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8121605128704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12220957282446).

8121605128704 is an abundant number, since it is smaller than the sum of its proper divisors (16320309436188).

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

8121605128704 is an frugal number, since it uses more digits than its factorization.

8121605128704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1162 (or 1119 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 45.

The spelling of 8121605128704 in words is "eight trillion, one hundred twenty-one billion, six hundred five million, one hundred twenty-eight thousand, seven hundred four".