1665506 has 8 divisors (see below), whose sum is σ = 2578944. Its totient is φ = 805860.

The previous prime is 1665493. The next prime is 1665523. The reversal of 1665506 is 6055661.

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

It is an Ulam 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 3 ways as a sum of consecutive naturals, for example, 13370 + ... + 13493.

It is an arithmetic number, because the mean of its divisors is an integer number (322368).

2^1665506 is an apocalyptic number.

1665506 is a deficient number, since it is larger than the sum of its proper divisors (913438).

1665506 is a wasteful number, since it uses less digits than its factorization.

1665506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26896.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 1665506 is about 1290.5448461793. The cubic root of 1665506 is about 118.5355813083.

The spelling of 1665506 in words is "one million, six hundred sixty-five thousand, five hundred six".