21220807320 has 96 divisors (see below), whose sum is σ = 69117768720. Its totient is φ = 5646562560.

The previous prime is 21220807313. The next prime is 21220807327. The reversal of 21220807320 is 2370802212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21220807313) and next prime (21220807327).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220807327) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 102027 + ... + 229893.

Almost surely, 2^21220807320 is an apocalyptic number.

21220807320 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 21220807320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34558884360).

21220807320 is an abundant number, since it is smaller than the sum of its proper divisors (47896961400).

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

21220807320 is a wasteful number, since it uses less digits than its factorization.

21220807320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128345 (or 128338 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The spelling of 21220807320 in words is "twenty-one billion, two hundred twenty million, eight hundred seven thousand, three hundred twenty".