21234423210 has 512 divisors, whose sum is σ = 72808243200. Its totient is φ = 3820400640.

The previous prime is 21234423167. The next prime is 21234423211. The reversal of 21234423210 is 1232443212.

It is a happy number.

It is a super-2 number, since 2×21234423210² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21234423211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 32221861 + ... + 32222519.

It is an arithmetic number, because the mean of its divisors is an integer number (142203600).

Almost surely, 2^21234423210 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21234423210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36404121600).

21234423210 is an abundant number, since it is smaller than the sum of its proper divisors (51573819990).

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

21234423210 is a wasteful number, since it uses less digits than its factorization.

21234423210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 766.

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21234423210 its reverse (1232443212), we get a palindrome (22466866422).

It can be divided in two parts, 21234 and 423210, that added together give a palindrome (444444).

The spelling of 21234423210 in words is "twenty-one billion, two hundred thirty-four million, four hundred twenty-three thousand, two hundred ten".