21203234430 has 128 divisors (see below), whose sum is σ = 60949324800. Its totient is φ = 4715383680.

The previous prime is 21203234417. The next prime is 21203234453. The reversal of 21203234430 is 3443230212.

It is a self number, because there is not a number n which added to its sum of digits gives 21203234430.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 352885 + ... + 408575.

It is an arithmetic number, because the mean of its divisors is an integer number (476166600).

Almost surely, 2^21203234430 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21203234430, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30474662400).

21203234430 is an abundant number, since it is smaller than the sum of its proper divisors (39746090370).

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

21203234430 is a wasteful number, since it uses less digits than its factorization.

21203234430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55759 (or 55745 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 24.

Adding to 21203234430 its reverse (3443230212), we get a palindrome (24646464642).

The spelling of 21203234430 in words is "twenty-one billion, two hundred three million, two hundred thirty-four thousand, four hundred thirty".