21344929 has 2 divisors, whose sum is σ = 21344930. Its totient is φ = 21344928.

The previous prime is 21344903. The next prime is 21344933. The reversal of 21344929 is 92944312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21344400 + 529 = 4620^2 + 23^2 .

It is a cyclic number.

It is not a de Polignac number, because 21344929 - 2⁹ = 21344417 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21344894 and 21344903.

It is not a weakly prime, because it can be changed into another prime (21344629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672464 + 10672465.

It is an arithmetic number, because the mean of its divisors is an integer number (10672465).

Almost surely, 2^21344929 is an apocalyptic number.

It is an amenable number.

21344929 is a deficient number, since it is larger than the sum of its proper divisors (1).

21344929 is an equidigital number, since it uses as much as digits as its factorization.

21344929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 34.

The square root of 21344929 is about 4620.0572507275. The cubic root of 21344929 is about 277.3947505525.

The spelling of 21344929 in words is "twenty-one million, three hundred forty-four thousand, nine hundred twenty-nine".