1666265 has 4 divisors (see below), whose sum is σ = 1999524. Its totient is φ = 1333008.

The previous prime is 1666261. The next prime is 1666271. The reversal of 1666265 is 5626661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5626661 = 1427 ⋅3943.

It can be written as a sum of positive squares in 2 ways, for example, as 1290496 + 375769 = 1136^2 + 613^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666265 - 2² = 1666261 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666261) 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, 166622 + ... + 166631.

It is an arithmetic number, because the mean of its divisors is an integer number (499881).

2^1666265 is an apocalyptic number.

It is an amenable number.

1666265 is a deficient number, since it is larger than the sum of its proper divisors (333259).

1666265 is an equidigital number, since it uses as much as digits as its factorization.

1666265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333258.

The product of its digits is 12960, while the sum is 32.

The square root of 1666265 is about 1290.8388745308. The cubic root of 1666265 is about 118.5535848146.

The spelling of 1666265 in words is "one million, six hundred sixty-six thousand, two hundred sixty-five".