21211123320 has 80 divisors (see below), whose sum is σ = 71292953160. Its totient is φ = 5656298688.

The previous prime is 21211123301. The next prime is 21211123321. The reversal of 21211123320 is 2332111212.

21211123320 is a `hidden beast` number, since 212 + 11 + 123 + 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 = 21211123293 and 21211123302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211123321) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3270082 + ... + 3276561.

Almost surely, 2^21211123320 is an apocalyptic number.

21211123320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211123320 is an abundant number, since it is smaller than the sum of its proper divisors (50081829840).

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

21211123320 is a wasteful number, since it uses less digits than its factorization.

21211123320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6546666 (or 6546653 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21211123320 its reverse (2332111212), we get a palindrome (23543234532).

The spelling of 21211123320 in words is "twenty-one billion, two hundred eleven million, one hundred twenty-three thousand, three hundred twenty".