1666506 has 8 divisors (see below), whose sum is σ = 3333024. Its totient is φ = 555500.

The previous prime is 1666499. The next prime is 1666507. The reversal of 1666506 is 6056661.

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

1666506 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (1666507) 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, 138870 + ... + 138881.

It is an arithmetic number, because the mean of its divisors is an integer number (416628).

2^1666506 is an apocalyptic number.

1666506 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1666506 is a wasteful number, since it uses less digits than its factorization.

1666506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277756.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 1666506 is about 1290.9322213037. The cubic root of 1666506 is about 118.5593001993.

The spelling of 1666506 in words is "one million, six hundred sixty-six thousand, five hundred six".