21203203320 has 384 divisors, whose sum is σ = 76712650560. Its totient is φ = 5046312960.

The previous prime is 21203203319. The next prime is 21203203381. The reversal of 21203203320 is 2330230212.

It is a happy number.

21203203320 is a `hidden beast` number, since 2 + 1 + 20 + 320 + 3 + 320 = 666.

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 = 21203203293 and 21203203302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 18106335 + ... + 18107505.

Almost surely, 2^21203203320 is an apocalyptic number.

21203203320 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 21203203320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38356325280).

21203203320 is an abundant number, since it is smaller than the sum of its proper divisors (55509447240).

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

21203203320 is a wasteful number, since it uses less digits than its factorization.

21203203320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1327 (or 1320 counting only the distinct ones).

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

Adding to 21203203320 its reverse (2330230212), we get a palindrome (23533433532).

The spelling of 21203203320 in words is "twenty-one billion, two hundred three million, two hundred three thousand, three hundred twenty".