309121 has 2 divisors, whose sum is σ = 309122. Its totient is φ = 309120.

The previous prime is 309109. The next prime is 309131. The reversal of 309121 is 121903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190096 + 119025 = 436^2 + 345^2 .

It is a cyclic number.

It is not a de Polignac number, because 309121 - 2¹³ = 300929 is a prime.

309121 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 309095 and 309104.

It is not a weakly prime, because it can be changed into another prime (309131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154560 + 154561.

It is an arithmetic number, because the mean of its divisors is an integer number (154561).

2³⁰⁹¹²¹ is an apocalyptic number.

It is an amenable number.

309121 is a deficient number, since it is larger than the sum of its proper divisors (1).

309121 is an equidigital number, since it uses as much as digits as its factorization.

309121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 309121 is about 555.9865106277. The cubic root of 309121 is about 67.6149664002.

The spelling of 309121 in words is "three hundred nine thousand, one hundred twenty-one".