20688329 has 2 divisors, whose sum is σ = 20688330. Its totient is φ = 20688328.

The previous prime is 20688301. The next prime is 20688341. The reversal of 20688329 is 92388602.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 76729 = 4540^2 + 277^2 .

It is a cyclic number.

It is not a de Polignac number, because 20688329 - 2¹⁶ = 20622793 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20688292 and 20688301.

It is not a weakly prime, because it can be changed into another prime (20688529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10344164 + 10344165.

It is an arithmetic number, because the mean of its divisors is an integer number (10344165).

Almost surely, 2^20688329 is an apocalyptic number.

It is an amenable number.

20688329 is a deficient number, since it is larger than the sum of its proper divisors (1).

20688329 is an equidigital number, since it uses as much as digits as its factorization.

20688329 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 20688329 is about 4548.4424806740. The cubic root of 20688329 is about 274.5207255285.

The spelling of 20688329 in words is "twenty million, six hundred eighty-eight thousand, three hundred twenty-nine".