308399989 has 2 divisors, whose sum is σ = 308399990. Its totient is φ = 308399988.

The previous prime is 308399983. The next prime is 308400011. The reversal of 308399989 is 989993803.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 287879089 + 20520900 = 16967^2 + 4530^2 .

It is a cyclic number.

It is not a de Polignac number, because 308399989 - 2³ = 308399981 is a prime.

It is a super-2 number, since 2×308399989² = 190221106430400242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (308399981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154199994 + 154199995.

It is an arithmetic number, because the mean of its divisors is an integer number (154199995).

Almost surely, 2^308399989 is an apocalyptic number.

It is an amenable number.

308399989 is a deficient number, since it is larger than the sum of its proper divisors (1).

308399989 is an equidigital number, since it uses as much as digits as its factorization.

308399989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3779136, while the sum is 58.

The square root of 308399989 is about 17561.3208216239. The cubic root of 308399989 is about 675.6235583991.

The spelling of 308399989 in words is "three hundred eight million, three hundred ninety-nine thousand, nine hundred eighty-nine".