21105709960608 has 3456 divisors, whose sum is σ = 88738315223040. Its totient is φ = 4745206333440.

The previous prime is 21105709960571. The next prime is 21105709960649. The reversal of 21105709960608 is 80606990750112.

21105709960608 is a `hidden beast` number, since 2 + 1 + 1 + 0 + 570 + 9 + 9 + 6 + 0 + 60 + 8 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 254285662135 + ... + 254285662217.

It is an arithmetic number, because the mean of its divisors is an integer number (25676595840).

Almost surely, 2^{21105709960608} is an apocalyptic number.

21105709960608 is a gapful number since it is divisible by the number (28) 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 21105709960608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44369157611520).

21105709960608 is an abundant number, since it is smaller than the sum of its proper divisors (67632605262432).

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

21105709960608 is a wasteful number, since it uses less digits than its factorization.

21105709960608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 54.

The spelling of 21105709960608 in words is "twenty-one trillion, one hundred five billion, seven hundred nine million, nine hundred sixty thousand, six hundred eight".