21164943634560 has 1024 divisors, whose sum is σ = 83109639168000. Its totient is φ = 5047440998400.

The previous prime is 21164943634453. The next prime is 21164943634577. The reversal of 21164943634560 is 6543634946112.

21164943634560 is a `hidden beast` number, since 2 + 1 + 1 + 6 + 4 + 9 + 43 + 6 + 34 + 560 = 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 = 21164943634497 and 21164943634506.

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, 5980485271 + ... + 5980488809.

It is an arithmetic number, because the mean of its divisors is an integer number (81161757000).

Almost surely, 2^{21164943634560} is an apocalyptic number.

21164943634560 is a gapful number since it is divisible by the number (20) 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 21164943634560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41554819584000).

21164943634560 is an abundant number, since it is smaller than the sum of its proper divisors (61944695533440).

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

21164943634560 is a wasteful number, since it uses less digits than its factorization.

21164943634560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4082 (or 4064 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 54.

The spelling of 21164943634560 in words is "twenty-one trillion, one hundred sixty-four billion, nine hundred forty-three million, six hundred thirty-four thousand, five hundred sixty".