1665766 has 4 divisors (see below), whose sum is σ = 2498652. Its totient is φ = 832882.

The previous prime is 1665761. The next prime is 1665767. The reversal of 1665766 is 6675661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6675661 = 41 ⋅162821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 416440 + ... + 416443.

It is an arithmetic number, because the mean of its divisors is an integer number (624663).

2^1665766 is an apocalyptic number.

1665766 is a deficient number, since it is larger than the sum of its proper divisors (832886).

1665766 is an equidigital number, since it uses as much as digits as its factorization.

1665766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832885.

The product of its digits is 45360, while the sum is 37.

The square root of 1665766 is about 1290.6455748965. The cubic root of 1665766 is about 118.5417491331.

The spelling of 1665766 in words is "one million, six hundred sixty-five thousand, seven hundred sixty-six".