20408329 has 4 divisors (see below), whose sum is σ = 20478276. Its totient is φ = 20338384.

The previous prime is 20408309. The next prime is 20408341. The reversal of 20408329 is 92380402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92380402 = 2 ⋅46190201.

It can be written as a sum of positive squares in 2 ways, for example, as 19598329 + 810000 = 4427^2 + 900^2 .

It is a cyclic number.

It is not a de Polignac number, because 20408329 - 2¹⁹ = 19884041 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20408297 and 20408306.

It is not an unprimeable number, because it can be changed into a prime (20408309) 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 in 3 ways as a sum of consecutive naturals, for example, 34534 + ... + 35119.

It is an arithmetic number, because the mean of its divisors is an integer number (5119569).

Almost surely, 2^20408329 is an apocalyptic number.

It is an amenable number.

20408329 is a deficient number, since it is larger than the sum of its proper divisors (69947).

20408329 is an equidigital number, since it uses as much as digits as its factorization.

20408329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69946.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 20408329 is about 4517.5578579582. The cubic root of 20408329 is about 273.2766230090.

The spelling of 20408329 in words is "twenty million, four hundred eight thousand, three hundred twenty-nine".