1667609 has 2 divisors, whose sum is σ = 1667610. Its totient is φ = 1667608.

The previous prime is 1667599. The next prime is 1667623. The reversal of 1667609 is 9067661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1651225 + 16384 = 1285^2 + 128^2 .

It is a cyclic number.

It is not a de Polignac number, because 1667609 - 2⁸ = 1667353 is a prime.

It is not a weakly prime, because it can be changed into another prime (1667629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833804 + 833805.

It is an arithmetic number, because the mean of its divisors is an integer number (833805).

2^1667609 is an apocalyptic number.

It is an amenable number.

1667609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1667609 is an equidigital number, since it uses as much as digits as its factorization.

1667609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 1667609 is about 1291.3593612934. The cubic root of 1667609 is about 118.5854511338.

The spelling of 1667609 in words is "one million, six hundred sixty-seven thousand, six hundred nine".