21827329 has 2 divisors, whose sum is σ = 21827330. Its totient is φ = 21827328.

The previous prime is 21827287. The next prime is 21827353. The reversal of 21827329 is 92372812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11068929 + 10758400 = 3327^2 + 3280^2 .

It is a cyclic number.

It is not a de Polignac number, because 21827329 - 2⁹ = 21826817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21827294 and 21827303.

It is not a weakly prime, because it can be changed into another prime (21827369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10913664 + 10913665.

It is an arithmetic number, because the mean of its divisors is an integer number (10913665).

Almost surely, 2^21827329 is an apocalyptic number.

It is an amenable number.

21827329 is a deficient number, since it is larger than the sum of its proper divisors (1).

21827329 is an equidigital number, since it uses as much as digits as its factorization.

21827329 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12096, while the sum is 34.

The square root of 21827329 is about 4671.9727096806. The cubic root of 21827329 is about 279.4689295907.

The spelling of 21827329 in words is "twenty-one million, eight hundred twenty-seven thousand, three hundred twenty-nine".