21424759 has 2 divisors, whose sum is σ = 21424760. Its totient is φ = 21424758.

The previous prime is 21424699. The next prime is 21424763. The reversal of 21424759 is 95742412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21424759 - 2⁷ = 21424631 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21424159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712379 + 10712380.

It is an arithmetic number, because the mean of its divisors is an integer number (10712380).

Almost surely, 2^21424759 is an apocalyptic number.

21424759 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424759 is an equidigital number, since it uses as much as digits as its factorization.

21424759 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 34.

The square root of 21424759 is about 4628.6886911954. The cubic root of 21424759 is about 277.7401389654.

The spelling of 21424759 in words is "twenty-one million, four hundred twenty-four thousand, seven hundred fifty-nine".