20321005 has 8 divisors (see below), whose sum is σ = 24410232. Its totient is φ = 16240128.

The previous prime is 20321003. The next prime is 20321009. The reversal of 20321005 is 50012302.

It can be written as a sum of positive squares in 4 ways, for example, as 3164841 + 17156164 = 1779^2 + 4142^2 .

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 20321005 - 2¹ = 20321003 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 (20321003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6457 + ... + 9073.

It is an arithmetic number, because the mean of its divisors is an integer number (3051279).

Almost surely, 2^20321005 is an apocalyptic number.

It is an amenable number.

20321005 is a deficient number, since it is larger than the sum of its proper divisors (4089227).

20321005 is a wasteful number, since it uses less digits than its factorization.

20321005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4175.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 20321005 is about 4507.8825406170. The cubic root of 20321005 is about 272.8862966678.

Adding to 20321005 its reverse (50012302), we get a palindrome (70333307).

The spelling of 20321005 in words is "twenty million, three hundred twenty-one thousand, five".