20307121 has 2 divisors, whose sum is σ = 20307122. Its totient is φ = 20307120.

The previous prime is 20307107. The next prime is 20307179. The reversal of 20307121 is 12170302.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20250000 + 57121 = 4500^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 20307121 - 2¹⁷ = 20176049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20307095 and 20307104.

It is not a weakly prime, because it can be changed into another prime (20307421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10153560 + 10153561.

It is an arithmetic number, because the mean of its divisors is an integer number (10153561).

Almost surely, 2^20307121 is an apocalyptic number.

It is an amenable number.

20307121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20307121 is an equidigital number, since it uses as much as digits as its factorization.

20307121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 20307121 is about 4506.3423083472. The cubic root of 20307121 is about 272.8241341167.

Adding to 20307121 its reverse (12170302), we get a palindrome (32477423).

The spelling of 20307121 in words is "twenty million, three hundred seven thousand, one hundred twenty-one".