1355509 has 4 divisors (see below), whose sum is σ = 1363180. Its totient is φ = 1347840.

The previous prime is 1355507. The next prime is 1355513. The reversal of 1355509 is 9055531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9055531 = 389 ⋅23279.

It can be written as a sum of positive squares in 2 ways, for example, as 253009 + 1102500 = 503^2 + 1050^2 .

It is a cyclic number.

It is not a de Polignac number, because 1355509 - 2¹ = 1355507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1355503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3564 + ... + 3925.

It is an arithmetic number, because the mean of its divisors is an integer number (340795).

2^1355509 is an apocalyptic number.

It is an amenable number.

1355509 is a deficient number, since it is larger than the sum of its proper divisors (7671).

1355509 is an equidigital number, since it uses as much as digits as its factorization.

1355509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7670.

The product of its (nonzero) digits is 3375, while the sum is 28.

The square root of 1355509 is about 1164.2632863747. The cubic root of 1355509 is about 110.6710767021.

Subtracting from 1355509 its sum of digits (28), we obtain a triangular number (1355481 = T₁₆₄₆).

The spelling of 1355509 in words is "one million, three hundred fifty-five thousand, five hundred nine".