21243220234 has 8 divisors (see below), whose sum is σ = 31938763968. Its totient is φ = 10596965580.

The previous prime is 21243220231. The next prime is 21243220253. The reversal of 21243220234 is 43202234212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21243220199 and 21243220208.

It is not an unprimeable number, because it can be changed into a prime (21243220231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12321192 + ... + 12322915.

It is an arithmetic number, because the mean of its divisors is an integer number (3992345496).

Almost surely, 2^21243220234 is an apocalyptic number.

21243220234 is a deficient number, since it is larger than the sum of its proper divisors (10695543734).

21243220234 is a wasteful number, since it uses less digits than its factorization.

21243220234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24644540.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 21243220234 its reverse (43202234212), we get a palindrome (64445454446).

The spelling of 21243220234 in words is "twenty-one billion, two hundred forty-three million, two hundred twenty thousand, two hundred thirty-four".