21204312234 has 48 divisors (see below), whose sum is σ = 49446710208. Its totient is φ = 6044347008.

The previous prime is 21204312223. The next prime is 21204312271. The reversal of 21204312234 is 43221340212.

It is a happy 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, 44019 + ... + 210585.

It is an arithmetic number, because the mean of its divisors is an integer number (1030139796).

Almost surely, 2^21204312234 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21204312234, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24723355104).

21204312234 is an abundant number, since it is smaller than the sum of its proper divisors (28242397974).

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

21204312234 is a wasteful number, since it uses less digits than its factorization.

21204312234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167019 (or 167012 counting only the distinct ones).

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

Adding to 21204312234 its reverse (43221340212), we get a palindrome (64425652446).

The spelling of 21204312234 in words is "twenty-one billion, two hundred four million, three hundred twelve thousand, two hundred thirty-four".