1664705 has 8 divisors (see below), whose sum is σ = 2283072. Its totient is φ = 1141488.

The previous prime is 1664701. The next prime is 1664711. The reversal of 1664705 is 5074661.

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 1664705 - 2² = 1664701 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23747 + ... + 23816.

It is an arithmetic number, because the mean of its divisors is an integer number (285384).

2^1664705 is an apocalyptic number.

It is an amenable number.

1664705 is a deficient number, since it is larger than the sum of its proper divisors (618367).

1664705 is an equidigital number, since it uses as much as digits as its factorization.

1664705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47575.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 1664705 is about 1290.2344748146. The cubic root of 1664705 is about 118.5165756276.

The spelling of 1664705 in words is "one million, six hundred sixty-four thousand, seven hundred five".