309121223 has 2 divisors, whose sum is σ = 309121224. Its totient is φ = 309121222.

The previous prime is 309121193. The next prime is 309121247. The reversal of 309121223 is 322121903.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 309121223 - 2¹⁰ = 309120199 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (309120223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154560611 + 154560612.

It is an arithmetic number, because the mean of its divisors is an integer number (154560612).

Almost surely, 2^309121223 is an apocalyptic number.

309121223 is a deficient number, since it is larger than the sum of its proper divisors (1).

309121223 is an equidigital number, since it uses as much as digits as its factorization.

309121223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 309121223 is about 17581.8435609011. The cubic root of 309121223 is about 676.1498265934.

The spelling of 309121223 in words is "three hundred nine million, one hundred twenty-one thousand, two hundred twenty-three".