21232321020 has 240 divisors, whose sum is σ = 74238262560. Its totient is φ = 5048303616.

The previous prime is 21232321009. The next prime is 21232321063. The reversal of 21232321020 is 2012323212.

It is a super-2 number, since 2×21232321020² (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 = 21232320984 and 21232321002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 502972 + ... + 543548.

It is an arithmetic number, because the mean of its divisors is an integer number (309326094).

Almost surely, 2^21232321020 is an apocalyptic number.

21232321020 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 21232321020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37119131280).

21232321020 is an abundant number, since it is smaller than the sum of its proper divisors (53005941540).

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

21232321020 is a wasteful number, since it uses less digits than its factorization.

21232321020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40634 (or 40623 counting only the distinct ones).

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

Adding to 21232321020 its reverse (2012323212), we get a palindrome (23244644232).

The spelling of 21232321020 in words is "twenty-one billion, two hundred thirty-two million, three hundred twenty-one thousand, twenty".