21243202320 has 80 divisors (see below), whose sum is σ = 69319938240. Its totient is φ = 5366702592.

The previous prime is 21243202319. The next prime is 21243202369. The reversal of 21243202320 is 2320234212.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2324739 + ... + 2333858.

It is an arithmetic number, because the mean of its divisors is an integer number (866499228).

Almost surely, 2^21243202320 is an apocalyptic number.

21243202320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21243202320 is an abundant number, since it is smaller than the sum of its proper divisors (48076735920).

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

21243202320 is a wasteful number, since it uses less digits than its factorization.

21243202320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4658632 (or 4658626 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

Adding to 21243202320 its reverse (2320234212), we get a palindrome (23563436532).

The spelling of 21243202320 in words is "twenty-one billion, two hundred forty-three million, two hundred two thousand, three hundred twenty".