1664345 has 8 divisors (see below), whose sum is σ = 2004864. Its totient is φ = 1326384.

The previous prime is 1664291. The next prime is 1664353. The reversal of 1664345 is 5434661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1664345 - 2¹⁸ = 1402201 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 1382 + ... + 2288.

It is an arithmetic number, because the mean of its divisors is an integer number (250608).

2^1664345 is an apocalyptic number.

It is an amenable number.

1664345 is a deficient number, since it is larger than the sum of its proper divisors (340519).

1664345 is an equidigital number, since it uses as much as digits as its factorization.

1664345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1279.

The product of its digits is 8640, while the sum is 29.

The square root of 1664345 is about 1290.0949577454. The cubic root of 1664345 is about 118.5080317629.

The spelling of 1664345 in words is "one million, six hundred sixty-four thousand, three hundred forty-five".