1666406 has 16 divisors (see below), whose sum is σ = 2934816. Its totient is φ = 694656.

The previous prime is 1666403. The next prime is 1666409. The reversal of 1666406 is 6046661.

It is an interprime number because it is at equal distance from previous prime (1666403) and next prime (1666409).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666403) 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, 1091 + ... + 2126.

It is an arithmetic number, because the mean of its divisors is an integer number (183426).

2^1666406 is an apocalyptic number.

1666406 is a deficient number, since it is larger than the sum of its proper divisors (1268410).

1666406 is a wasteful number, since it uses less digits than its factorization.

1666406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3263.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 1666406 is about 1290.8934890222. The cubic root of 1666406 is about 118.5569287373.

The spelling of 1666406 in words is "one million, six hundred sixty-six thousand, four hundred six".