309453421 has 2 divisors, whose sum is σ = 309453422. Its totient is φ = 309453420.

The previous prime is 309453401. The next prime is 309453433. The reversal of 309453421 is 124354903.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179265321 + 130188100 = 13389^2 + 11410^2 .

It is a cyclic number.

It is not a de Polignac number, because 309453421 - 2⁹ = 309452909 is a prime.

It is a super-5 number, since 5×309453421⁵ (a number of 44 digits) contains 55555 as substring. Note that it is a super-d number also for d = 2.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (309453401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154726710 + 154726711.

It is an arithmetic number, because the mean of its divisors is an integer number (154726711).

Almost surely, 2^309453421 is an apocalyptic number.

It is an amenable number.

309453421 is a deficient number, since it is larger than the sum of its proper divisors (1).

309453421 is an equidigital number, since it uses as much as digits as its factorization.

309453421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 309453421 is about 17591.2882132037. The cubic root of 309453421 is about 676.3919486587.

The spelling of 309453421 in words is "three hundred nine million, four hundred fifty-three thousand, four hundred twenty-one".