20680321 has 4 divisors (see below), whose sum is σ = 20778544. Its totient is φ = 20582100.

The previous prime is 20680271. The next prime is 20680333. The reversal of 20680321 is 12308602.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12308602 = 2 ⋅6154301.

It is a cyclic number.

It is not a de Polignac number, because 20680321 - 2¹⁵ = 20647553 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20680292 and 20680301.

It is not an unprimeable number, because it can be changed into a prime (20680391) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48795 + ... + 49216.

It is an arithmetic number, because the mean of its divisors is an integer number (5194636).

Almost surely, 2^20680321 is an apocalyptic number.

It is an amenable number.

20680321 is a deficient number, since it is larger than the sum of its proper divisors (98223).

20680321 is an equidigital number, since it uses as much as digits as its factorization.

20680321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98222.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 20680321 is about 4547.5620941335. The cubic root of 20680321 is about 274.4853006330.

Adding to 20680321 its reverse (12308602), we get a palindrome (32988923).

The spelling of 20680321 in words is "twenty million, six hundred eighty thousand, three hundred twenty-one".