21232123220 has 96 divisors (see below), whose sum is σ = 57506561280. Its totient is φ = 6389591040.

The previous prime is 21232123217. The next prime is 21232123223. The reversal of 21232123220 is 2232123212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21232123217) and next prime (21232123223).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21232123192 and 21232123201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232123223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 193049 + ... + 282368.

It is an arithmetic number, because the mean of its divisors is an integer number (599026680).

Almost surely, 2^21232123220 is an apocalyptic number.

21232123220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21232123220 is an abundant number, since it is smaller than the sum of its proper divisors (36274438060).

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

21232123220 is a wasteful number, since it uses less digits than its factorization.

21232123220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475473 (or 475471 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21232123220 its reverse (2232123212), we get a palindrome (23464246432).

The spelling of 21232123220 in words is "twenty-one billion, two hundred thirty-two million, one hundred twenty-three thousand, two hundred twenty".