20312321 has 4 divisors (see below), whose sum is σ = 20509632. Its totient is φ = 20115012.

The previous prime is 20312309. The next prime is 20312351. The reversal of 20312321 is 12321302.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20312321 - 2¹⁰ = 20311297 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20312296 and 20312305.

It is not an unprimeable number, because it can be changed into a prime (20312351) 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, 98501 + ... + 98706.

It is an arithmetic number, because the mean of its divisors is an integer number (5127408).

Almost surely, 2^20312321 is an apocalyptic number.

It is an amenable number.

20312321 is a deficient number, since it is larger than the sum of its proper divisors (197311).

20312321 is a wasteful number, since it uses less digits than its factorization.

20312321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197310.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 20312321 is about 4506.9192360192. The cubic root of 20312321 is about 272.8474192888.

Adding to 20312321 its reverse (12321302), we get a palindrome (32633623).

The spelling of 20312321 in words is "twenty million, three hundred twelve thousand, three hundred twenty-one".