21358328320 has 320 divisors, whose sum is σ = 61482136320. Its totient is φ = 6961102848.

The previous prime is 21358328249. The next prime is 21358328347. The reversal of 21358328320 is 2382385312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (320).

It is a self number, because there is not a number n which added to its sum of digits gives 21358328320.

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, 37936359 + ... + 37936921.

It is an arithmetic number, because the mean of its divisors is an integer number (192131676).

Almost surely, 2^21358328320 is an apocalyptic number.

21358328320 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 21358328320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30741068160).

21358328320 is an abundant number, since it is smaller than the sum of its proper divisors (40123808000).

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

21358328320 is an equidigital number, since it uses as much as digits as its factorization.

21358328320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695 (or 679 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The spelling of 21358328320 in words is "twenty-one billion, three hundred fifty-eight million, three hundred twenty-eight thousand, three hundred twenty".