21824329 has 2 divisors, whose sum is σ = 21824330. Its totient is φ = 21824328.

The previous prime is 21824317. The next prime is 21824353. The reversal of 21824329 is 92342812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16418704 + 5405625 = 4052^2 + 2325^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21824329 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21824329.

It is not a weakly prime, because it can be changed into another prime (21824359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10912164 + 10912165.

It is an arithmetic number, because the mean of its divisors is an integer number (10912165).

Almost surely, 2^21824329 is an apocalyptic number.

It is an amenable number.

21824329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21824329 is an equidigital number, since it uses as much as digits as its factorization.

21824329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 31.

The square root of 21824329 is about 4671.6516351286. The cubic root of 21824329 is about 279.4561253793.

The spelling of 21824329 in words is "twenty-one million, eight hundred twenty-four thousand, three hundred twenty-nine".