1366665 has 16 divisors (see below), whose sum is σ = 2203200. Its totient is φ = 723392.

The previous prime is 1366663. The next prime is 1366667. The reversal of 1366665 is 5666631.

It is an interprime number because it is at equal distance from previous prime (1366663) and next prime (1366667).

It is a cyclic number.

It is not a de Polignac number, because 1366665 - 2¹ = 1366663 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1366661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2431 + ... + 2939.

It is an arithmetic number, because the mean of its divisors is an integer number (137700).

2^1366665 is an apocalyptic number.

1366665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1366665 is a deficient number, since it is larger than the sum of its proper divisors (836535).

1366665 is a wasteful number, since it uses less digits than its factorization.

1366665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696.

The product of its digits is 19440, while the sum is 33.

The square root of 1366665 is about 1169.0444816174. The cubic root of 1366665 is about 110.9738596021.

It can be divided in two parts, 13666 and 65, that added together give a palindrome (13731).

The spelling of 1366665 in words is "one million, three hundred sixty-six thousand, six hundred sixty-five".