20308121 has 2 divisors, whose sum is σ = 20308122. Its totient is φ = 20308120.

The previous prime is 20308111. The next prime is 20308129. The reversal of 20308121 is 12180302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14714896 + 5593225 = 3836^2 + 2365^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20308121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20308121.

It is not a weakly prime, because it can be changed into another prime (20308129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10154060 + 10154061.

It is an arithmetic number, because the mean of its divisors is an integer number (10154061).

Almost surely, 2^20308121 is an apocalyptic number.

It is an amenable number.

20308121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20308121 is an equidigital number, since it uses as much as digits as its factorization.

20308121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 20308121 is about 4506.4532617126. The cubic root of 20308121 is about 272.8286123431.

Adding to 20308121 its reverse (12180302), we get a palindrome (32488423).

The spelling of 20308121 in words is "twenty million, three hundred eight thousand, one hundred twenty-one".