21320203320 has 128 divisors (see below), whose sum is σ = 76534113600. Its totient is φ = 5248046592.

The previous prime is 21320203271. The next prime is 21320203321. The reversal of 21320203320 is 2330202312.

It is a happy number.

21320203320 is a `hidden beast` number, since 2 + 1 + 320 + 20 + 3 + 320 = 666.

It is a super-2 number, since 2×21320203320² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21320203293 and 21320203302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320203321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 745227 + ... + 773306.

Almost surely, 2^21320203320 is an apocalyptic number.

21320203320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21320203320 is an abundant number, since it is smaller than the sum of its proper divisors (55213910280).

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

21320203320 is a wasteful number, since it uses less digits than its factorization.

21320203320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1518566 (or 1518556 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

Adding to 21320203320 its reverse (2330202312), we get a palindrome (23650405632).

The spelling of 21320203320 in words is "twenty-one billion, three hundred twenty million, two hundred three thousand, three hundred twenty".