1664206 has 4 divisors (see below), whose sum is σ = 2496312. Its totient is φ = 832102.

The previous prime is 1664123. The next prime is 1664227. The reversal of 1664206 is 6024661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×1664206² = 5539163220872, which contains 22 as substring.

It is a congruent 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 as a sum of consecutive naturals, namely, 416050 + ... + 416053.

It is an arithmetic number, because the mean of its divisors is an integer number (624078).

2^1664206 is an apocalyptic number.

1664206 is a deficient number, since it is larger than the sum of its proper divisors (832106).

1664206 is an equidigital number, since it uses as much as digits as its factorization.

1664206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832105.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 1664206 is about 1290.0410846171. The cubic root of 1664206 is about 118.5047325521.

Adding to 1664206 its reverse (6024661), we get a palindrome (7688867).

The spelling of 1664206 in words is "one million, six hundred sixty-four thousand, two hundred six".