21210343320 has 128 divisors (see below), whose sum is σ = 66448512000. Its totient is φ = 5406027264.

The previous prime is 21210343309. The next prime is 21210343339. The reversal of 21210343320 is 2334301212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5377269 + ... + 5381211.

It is an arithmetic number, because the mean of its divisors is an integer number (519129000).

Almost surely, 2^21210343320 is an apocalyptic number.

21210343320 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 21210343320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33224256000).

21210343320 is an abundant number, since it is smaller than the sum of its proper divisors (45238168680).

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

21210343320 is a wasteful number, since it uses less digits than its factorization.

21210343320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5929 (or 5925 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21210343320 its reverse (2334301212), we get a palindrome (23544644532).

The spelling of 21210343320 in words is "twenty-one billion, two hundred ten million, three hundred forty-three thousand, three hundred twenty".