21323012220 has 72 divisors (see below), whose sum is σ = 64691827200. Its totient is φ = 5685079680.

The previous prime is 21323012203. The next prime is 21323012251. The reversal of 21323012220 is 2221032312.

21323012220 is a `hidden beast` number, since 213 + 230 + 1 + 2 + 220 = 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 = 21323012193 and 21323012202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1676485 + ... + 1689155.

It is an arithmetic number, because the mean of its divisors is an integer number (898497600).

Almost surely, 2^21323012220 is an apocalyptic number.

21323012220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21323012220 is an abundant number, since it is smaller than the sum of its proper divisors (43368814980).

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

21323012220 is a wasteful number, since it uses less digits than its factorization.

21323012220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22035 (or 22030 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21323012220 its reverse (2221032312), we get a palindrome (23544044532).

It can be divided in two parts, 2132301 and 2220, that added together give a square (2134521 = 1461²).

The spelling of 21323012220 in words is "twenty-one billion, three hundred twenty-three million, twelve thousand, two hundred twenty".