1405666 has 16 divisors (see below), whose sum is σ = 2187000. Its totient is φ = 677248.

The previous prime is 1405643. The next prime is 1405669. The reversal of 1405666 is 6665041.

It can be written as a sum of positive squares in 4 ways, for example, as 874225 + 531441 = 935^2 + 729^2 .

It is not an unprimeable number, because it can be changed into a prime (1405669) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 9360 + ... + 9508.

2^1405666 is an apocalyptic number.

1405666 is a deficient number, since it is larger than the sum of its proper divisors (781334).

1405666 is a wasteful number, since it uses less digits than its factorization.

1405666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 1405666 is about 1185.6078609726. The cubic root of 1405666 is about 112.0196075365.

The spelling of 1405666 in words is "one million, four hundred five thousand, six hundred sixty-six".