20212321 has 4 divisors (see below), whose sum is σ = 20225044. Its totient is φ = 20199600.

The previous prime is 20212319. The next prime is 20212327. The reversal of 20212321 is 12321202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12321202 = 2 ⋅6160601.

It can be written as a sum of positive squares in 2 ways, for example, as 2446096 + 17766225 = 1564^2 + 4215^2 .

It is a cyclic number.

It is not a de Polignac number, because 20212321 - 2¹ = 20212319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20212327) 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, 3570 + ... + 7291.

It is an arithmetic number, because the mean of its divisors is an integer number (5056261).

Almost surely, 2^20212321 is an apocalyptic number.

It is an amenable number.

20212321 is a deficient number, since it is larger than the sum of its proper divisors (12723).

20212321 is a wasteful number, since it uses less digits than its factorization.

20212321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12722.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20212321 is about 4495.8114951586. The cubic root of 20212321 is about 272.3989289340.

Adding to 20212321 its reverse (12321202), we get a palindrome (32533523).

It can be divided in two parts, 202 and 12321, that multiplied together give a palindrome (2488842).

The spelling of 20212321 in words is "twenty million, two hundred twelve thousand, three hundred twenty-one".