6401509 has 2 divisors, whose sum is σ = 6401510. Its totient is φ = 6401508.

The previous prime is 6401497. The next prime is 6401533. The reversal of 6401509 is 9051046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5536609 + 864900 = 2353^2 + 930^2 .

It is a cyclic number.

It is not a de Polignac number, because 6401509 - 2⁵ = 6401477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6401569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3200754 + 3200755.

It is an arithmetic number, because the mean of its divisors is an integer number (3200755).

Almost surely, 2^6401509 is an apocalyptic number.

It is an amenable number.

6401509 is a deficient number, since it is larger than the sum of its proper divisors (1).

6401509 is an equidigital number, since it uses as much as digits as its factorization.

6401509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 6401509 is about 2530.1203528686. The cubic root of 6401509 is about 185.6781441927.

The spelling of 6401509 in words is "six million, four hundred one thousand, five hundred nine".