6390409 has 2 divisors, whose sum is σ = 6390410. Its totient is φ = 6390408.

The previous prime is 6390407. The next prime is 6390413. The reversal of 6390409 is 9040936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3717184 + 2673225 = 1928^2 + 1635^2 .

It is a cyclic number.

It is not a de Polignac number, because 6390409 - 2¹ = 6390407 is a prime.

Together with 6390407, it forms a pair of twin primes.

6390409 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (6390401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3195204 + 3195205.

It is an arithmetic number, because the mean of its divisors is an integer number (3195205).

Almost surely, 2^6390409 is an apocalyptic number.

It is an amenable number.

6390409 is a deficient number, since it is larger than the sum of its proper divisors (1).

6390409 is an equidigital number, since it uses as much as digits as its factorization.

6390409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 6390409 is about 2527.9258296081. The cubic root of 6390409 is about 185.5707622301.

The spelling of 6390409 in words is "six million, three hundred ninety thousand, four hundred nine".