21730320420 has 48 divisors (see below), whose sum is σ = 63490331520. Its totient is φ = 5542806016.

The previous prime is 21730320419. The next prime is 21730320433. The reversal of 21730320420 is 2402303712.

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, 7871925 + ... + 7874684.

It is an arithmetic number, because the mean of its divisors is an integer number (1322715240).

Almost surely, 2^21730320420 is an apocalyptic number.

21730320420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21730320420 is an abundant number, since it is smaller than the sum of its proper divisors (41760011100).

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

21730320420 is a wasteful number, since it uses less digits than its factorization.

21730320420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15746644 (or 15746642 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 24.

The spelling of 21730320420 in words is "twenty-one billion, seven hundred thirty million, three hundred twenty thousand, four hundred twenty".