20321813 has 8 divisors (see below), whose sum is σ = 21042048. Its totient is φ = 19613664.

The previous prime is 20321759. The next prime is 20321867. The reversal of 20321813 is 31812302.

It is an interprime number because it is at equal distance from previous prime (20321759) and next prime (20321867).

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

It is not a de Polignac number, because 20321813 - 2⁸ = 20321557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321893) 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, 470 + ... + 6392.

It is an arithmetic number, because the mean of its divisors is an integer number (2630256).

Almost surely, 2^20321813 is an apocalyptic number.

It is an amenable number.

20321813 is a deficient number, since it is larger than the sum of its proper divisors (720235).

20321813 is an equidigital number, since it uses as much as digits as its factorization.

20321813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6043.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 20321813 is about 4507.9721605174. The cubic root of 20321813 is about 272.8899134379.

The spelling of 20321813 in words is "twenty million, three hundred twenty-one thousand, eight hundred thirteen".