1365561 has 6 divisors (see below), whose sum is σ = 1972490. Its totient is φ = 910368.

The previous prime is 1365557. The next prime is 1365563. The reversal of 1365561 is 1655631.

It is a happy number.

1365561 is a `hidden beast` number, since 1 + 3 + 655 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1089936 + 275625 = 1044^2 + 525^2 .

It is not a de Polignac number, because 1365561 - 2² = 1365557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1365563) 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 5 ways as a sum of consecutive naturals, for example, 75856 + ... + 75873.

2^1365561 is an apocalyptic number.

It is an amenable number.

1365561 is a deficient number, since it is larger than the sum of its proper divisors (606929).

1365561 is a wasteful number, since it uses less digits than its factorization.

1365561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151735 (or 151732 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

The square root of 1365561 is about 1168.5722057280. The cubic root of 1365561 is about 110.9439697741.

The spelling of 1365561 in words is "one million, three hundred sixty-five thousand, five hundred sixty-one".