21202121320320 has 256 divisors, whose sum is σ = 68737451731200. Its totient is φ = 5557242445824.

The previous prime is 21202121320277. The next prime is 21202121320321. The reversal of 21202121320320 is 2302312120212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202121320321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1276997139 + ... + 1277013741.

It is an arithmetic number, because the mean of its divisors is an integer number (268505670825).

Almost surely, 2^{21202121320320} is an apocalyptic number.

21202121320320 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 21202121320320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34368725865600).

21202121320320 is an abundant number, since it is smaller than the sum of its proper divisors (47535330410880).

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

21202121320320 is a wasteful number, since it uses less digits than its factorization.

21202121320320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27957 (or 27945 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

Adding to 21202121320320 its reverse (2302312120212), we get a palindrome (23504433440532).

The spelling of 21202121320320 in words is "twenty-one trillion, two hundred two billion, one hundred twenty-one million, three hundred twenty thousand, three hundred twenty".