6401609 has 2 divisors, whose sum is σ = 6401610. Its totient is φ = 6401608.

The previous prime is 6401587. The next prime is 6401621. The reversal of 6401609 is 9061046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6017209 + 384400 = 2453^2 + 620^2 .

It is a cyclic number.

It is not a de Polignac number, because 6401609 - 2¹⁶ = 6336073 is a prime.

It is a Chen prime.

It is an Ulam number.

It is equal to p₄₃₈₅₀₆ and since 6401609 and 438506 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (6401669) 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, 3200804 + 3200805.

It is an arithmetic number, because the mean of its divisors is an integer number (3200805).

Almost surely, 2^6401609 is an apocalyptic number.

It is an amenable number.

6401609 is a deficient number, since it is larger than the sum of its proper divisors (1).

6401609 is an equidigital number, since it uses as much as digits as its factorization.

6401609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 6401609 is about 2530.1401146972. The cubic root of 6401609 is about 185.6791110334.

The spelling of 6401609 in words is "six million, four hundred one thousand, six hundred nine".