21234243 has 16 divisors (see below), whose sum is σ = 29082240. Its totient is φ = 13776576.

The previous prime is 21234211. The next prime is 21234281. The reversal of 21234243 is 34243212.

It is not a de Polignac number, because 21234243 - 2⁵ = 21234211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21234203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17296 + ... + 18482.

It is an arithmetic number, because the mean of its divisors is an integer number (1817640).

Almost surely, 2^21234243 is an apocalyptic number.

21234243 is a deficient number, since it is larger than the sum of its proper divisors (7847997).

21234243 is a wasteful number, since it uses less digits than its factorization.

21234243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1346.

The product of its digits is 1152, while the sum is 21.

The square root of 21234243 is about 4608.0628250926. The cubic root of 21234243 is about 276.9144344228.

Adding to 21234243 its reverse (34243212), we get a palindrome (55477455).

The spelling of 21234243 in words is "twenty-one million, two hundred thirty-four thousand, two hundred forty-three".