21424027 has 2 divisors, whose sum is σ = 21424028. Its totient is φ = 21424026.

The previous prime is 21424003. The next prime is 21424049. The reversal of 21424027 is 72042412.

It is a happy number.

It is an a-pointer prime, because the next prime (21424049) can be obtained adding 21424027 to its sum of digits (22).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21424027 - 2¹⁵ = 21391259 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21423989 and 21424007.

It is not a weakly prime, because it can be changed into another prime (21424087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712013 + 10712014.

It is an arithmetic number, because the mean of its divisors is an integer number (10712014).

Almost surely, 2^21424027 is an apocalyptic number.

21424027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424027 is an equidigital number, since it uses as much as digits as its factorization.

21424027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 21424027 is about 4628.6096184492. The cubic root of 21424027 is about 277.7369758322.

Adding to 21424027 its reverse (72042412), we get a palindrome (93466439).

The spelling of 21424027 in words is "twenty-one million, four hundred twenty-four thousand, twenty-seven".