312400009 has 2 divisors, whose sum is σ = 312400010. Its totient is φ = 312400008.

The previous prime is 312400003. The next prime is 312400019. The reversal of 312400009 is 900004213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 291897225 + 20502784 = 17085^2 + 4528^2 .

It is an emirp because it is prime and its reverse (900004213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 312400009 - 2³ = 312400001 is a prime.

It is not a weakly prime, because it can be changed into another prime (312400001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156200004 + 156200005.

It is an arithmetic number, because the mean of its divisors is an integer number (156200005).

Almost surely, 2^312400009 is an apocalyptic number.

It is an amenable number.

312400009 is a deficient number, since it is larger than the sum of its proper divisors (1).

312400009 is an equidigital number, since it uses as much as digits as its factorization.

312400009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 312400009 is about 17674.8411308277. The cubic root of 312400009 is about 678.5320184726.

The spelling of 312400009 in words is "three hundred twelve million, four hundred thousand, nine".