1966666 has 8 divisors (see below), whose sum is σ = 3176964. Its totient is φ = 907680.

The previous prime is 1966663. The next prime is 1966667. The reversal of 1966666 is 6666691.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1901641 + 65025 = 1379^2 + 255^2 .

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

1966666 is a modest number, since divided by 6666 gives 196 as remainder.

It is not an unprimeable number, because it can be changed into a prime (1966663) 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, 37795 + ... + 37846.

2^1966666 is an apocalyptic number.

1966666 is a deficient number, since it is larger than the sum of its proper divisors (1210298).

1966666 is a wasteful number, since it uses less digits than its factorization.

1966666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75656.

The product of its digits is 69984, while the sum is 40.

The square root of 1966666 is about 1402.3786935061. The cubic root of 1966666 is about 125.2882096376.

It can be divided in two parts, 196 and 6666, that multiplied together give a triangular number (1306536 = T₁₆₁₆).

The spelling of 1966666 in words is "one million, nine hundred sixty-six thousand, six hundred sixty-six".