21424367 has 2 divisors, whose sum is σ = 21424368. Its totient is φ = 21424366.

The previous prime is 21424357. The next prime is 21424373. The reversal of 21424367 is 76342412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21424367 - 2⁶ = 21424303 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21424327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712183 + 10712184.

It is an arithmetic number, because the mean of its divisors is an integer number (10712184).

Almost surely, 2^21424367 is an apocalyptic number.

21424367 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424367 is an equidigital number, since it uses as much as digits as its factorization.

21424367 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 29.

The square root of 21424367 is about 4628.6463463955. The cubic root of 21424367 is about 277.7384450560.

Adding to 21424367 its reverse (76342412), we get a palindrome (97766779).

The spelling of 21424367 in words is "twenty-one million, four hundred twenty-four thousand, three hundred sixty-seven".