20328305 has 4 divisors (see below), whose sum is σ = 24393972. Its totient is φ = 16262640.

The previous prime is 20328257. The next prime is 20328307. The reversal of 20328305 is 50382302.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50382302 = 2 ⋅25191151.

It can be written as a sum of positive squares in 2 ways, for example, as 7661824 + 12666481 = 2768^2 + 3559^2 .

It is not a de Polignac number, because 20328305 - 2¹⁸ = 20066161 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20328307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2032826 + ... + 2032835.

It is an arithmetic number, because the mean of its divisors is an integer number (6098493).

Almost surely, 2^20328305 is an apocalyptic number.

It is an amenable number.

20328305 is a deficient number, since it is larger than the sum of its proper divisors (4065667).

20328305 is an equidigital number, since it uses as much as digits as its factorization.

20328305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4065666.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 20328305 is about 4508.6921607047. The cubic root of 20328305 is about 272.9189694527.

The spelling of 20328305 in words is "twenty million, three hundred twenty-eight thousand, three hundred five".