1664423 has 4 divisors (see below), whose sum is σ = 1681680. Its totient is φ = 1647168.

The previous prime is 1664417. The next prime is 1664431. The reversal of 1664423 is 3244661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3244661 = 7 ⋅463523.

It is a cyclic number.

It is not a de Polignac number, because 1664423 - 2⁴ = 1664407 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1664392 and 1664401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8483 + ... + 8676.

It is an arithmetic number, because the mean of its divisors is an integer number (420420).

2^1664423 is an apocalyptic number.

1664423 is a deficient number, since it is larger than the sum of its proper divisors (17257).

1664423 is an equidigital number, since it uses as much as digits as its factorization.

1664423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17256.

The product of its digits is 3456, while the sum is 26.

The square root of 1664423 is about 1290.1251877240. The cubic root of 1664423 is about 118.5098830381.

The spelling of 1664423 in words is "one million, six hundred sixty-four thousand, four hundred twenty-three".