1365643 has 4 divisors (see below), whose sum is σ = 1409728. Its totient is φ = 1321560.

The previous prime is 1365583. The next prime is 1365659. The reversal of 1365643 is 3465631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3465631 = 13 ⋅266587.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1365643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1365043) 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 3 ways as a sum of consecutive naturals, for example, 21996 + ... + 22057.

It is an arithmetic number, because the mean of its divisors is an integer number (352432).

2^1365643 is an apocalyptic number.

1365643 is a deficient number, since it is larger than the sum of its proper divisors (44085).

1365643 is an equidigital number, since it uses as much as digits as its factorization.

1365643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44084.

The product of its digits is 6480, while the sum is 28.

The square root of 1365643 is about 1168.6072907525. The cubic root of 1365643 is about 110.9461904056.

It can be divided in two parts, 13 and 65643, that added together give a palindrome (65656).

The spelling of 1365643 in words is "one million, three hundred sixty-five thousand, six hundred forty-three".