21017204625320 has 128 divisors (see below), whose sum is σ = 48295720661760. Its totient is φ = 8229278453760.

The previous prime is 21017204625311. The next prime is 21017204625323. The reversal of 21017204625320 is 2352640271012.

It is not an unprimeable number, because it can be changed into a prime (21017204625323) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 449763797 + ... + 449810523.

It is an arithmetic number, because the mean of its divisors is an integer number (377310317670).

Almost surely, 2^{21017204625320} is an apocalyptic number.

21017204625320 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 21017204625320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24147860330880).

21017204625320 is an abundant number, since it is smaller than the sum of its proper divisors (27278516036440).

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

21017204625320 is a wasteful number, since it uses less digits than its factorization.

21017204625320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47683 (or 47679 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

Adding to 21017204625320 its reverse (2352640271012), we get a palindrome (23369844896332).

The spelling of 21017204625320 in words is "twenty-one trillion, seventeen billion, two hundred four million, six hundred twenty-five thousand, three hundred twenty".