308402209 has 2 divisors, whose sum is σ = 308402210. Its totient is φ = 308402208.

The previous prime is 308402201. The next prime is 308402221. The reversal of 308402209 is 902204803.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 255520225 + 52881984 = 15985^2 + 7272^2 .

It is an emirp because it is prime and its reverse (902204803) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 308402209 - 2³ = 308402201 is a prime.

It is a super-2 number, since 2×308402209² = 190223845032159362, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (308402201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154201104 + 154201105.

It is an arithmetic number, because the mean of its divisors is an integer number (154201105).

Almost surely, 2^308402209 is an apocalyptic number.

It is an amenable number.

308402209 is a deficient number, since it is larger than the sum of its proper divisors (1).

308402209 is an equidigital number, since it uses as much as digits as its factorization.

308402209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 308402209 is about 17561.3840286009. The cubic root of 308402209 is about 675.6251795413.

The spelling of 308402209 in words is "three hundred eight million, four hundred two thousand, two hundred nine".