21344243 has 2 divisors, whose sum is σ = 21344244. Its totient is φ = 21344242.

The previous prime is 21344237. The next prime is 21344249. The reversal of 21344243 is 34244312.

It is a balanced prime because it is at equal distance from previous prime (21344237) and next prime (21344249).

It is a cyclic number.

It is not a de Polignac number, because 21344243 - 2¹² = 21340147 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21344249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672121 + 10672122.

It is an arithmetic number, because the mean of its divisors is an integer number (10672122).

Almost surely, 2^21344243 is an apocalyptic number.

21344243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21344243 is an equidigital number, since it uses as much as digits as its factorization.

21344243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 23.

The square root of 21344243 is about 4619.9830086268. The cubic root of 21344243 is about 277.3917788109.

Adding to 21344243 its reverse (34244312), we get a palindrome (55588555).

The spelling of 21344243 in words is "twenty-one million, three hundred forty-four thousand, two hundred forty-three".