21164104021320 has 384 divisors, whose sum is σ = 76932671961600. Its totient is φ = 5012359391232.

The previous prime is 21164104021289. The next prime is 21164104021327. The reversal of 21164104021320 is 2312040146112.

21164104021320 is a `hidden beast` number, since 2 + 1 + 1 + 641 + 0 + 4 + 0 + 2 + 13 + 2 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (21164104021327) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12162234 + ... + 13793046.

It is an arithmetic number, because the mean of its divisors is an integer number (200345499900).

Almost surely, 2^{21164104021320} is an apocalyptic number.

21164104021320 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 21164104021320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38466335980800).

21164104021320 is an abundant number, since it is smaller than the sum of its proper divisors (55768567940280).

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

21164104021320 is a wasteful number, since it uses less digits than its factorization.

21164104021320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630949 (or 1630942 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

Adding to 21164104021320 its reverse (2312040146112), we get a palindrome (23476144167432).

The spelling of 21164104021320 in words is "twenty-one trillion, one hundred sixty-four billion, one hundred four million, twenty-one thousand, three hundred twenty".