20306945 has 8 divisors (see below), whose sum is σ = 24399144. Its totient is φ = 16225024.

The previous prime is 20306941. The next prime is 20306971. The reversal of 20306945 is 54960302.

It can be written as a sum of positive squares in 4 ways, for example, as 5798464 + 14508481 = 2408^2 + 3809^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20306945 - 2² = 20306941 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20306941) 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 7 ways as a sum of consecutive naturals, for example, 2807 + ... + 6963.

It is an arithmetic number, because the mean of its divisors is an integer number (3049893).

Almost surely, 2^20306945 is an apocalyptic number.

It is an amenable number.

20306945 is a deficient number, since it is larger than the sum of its proper divisors (4092199).

20306945 is an equidigital number, since it uses as much as digits as its factorization.

20306945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5139.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 20306945 is about 4506.3227802722. The cubic root of 20306945 is about 272.8233459336.

The spelling of 20306945 in words is "twenty million, three hundred six thousand, nine hundred forty-five".