121309 has 2 divisors, whose sum is σ = 121310. Its totient is φ = 121308.

The previous prime is 121291. The next prime is 121313. The reversal of 121309 is 903121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120409 + 900 = 347^2 + 30^2 .

It is a cyclic number.

It is not a de Polignac number, because 121309 - 2⁷ = 121181 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121292 and 121301.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60654 + 60655.

It is an arithmetic number, because the mean of its divisors is an integer number (60655).

2¹²¹³⁰⁹ is an apocalyptic number.

It is an amenable number.

121309 is a deficient number, since it is larger than the sum of its proper divisors (1).

121309 is an equidigital number, since it uses as much as digits as its factorization.

121309 is an evil number, because the sum of its binary digits is even.

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

The square root of 121309 is about 348.2944156888. The cubic root of 121309 is about 49.5029417019.

The spelling of 121309 in words is "one hundred twenty-one thousand, three hundred nine".