1535509 has 4 divisors (see below), whose sum is σ = 1540480. Its totient is φ = 1530540.

The previous prime is 1535507. The next prime is 1535531. The reversal of 1535509 is 9055351.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9055351 = 619 ⋅14629.

It is a cyclic number.

It is not a de Polignac number, because 1535509 - 2¹ = 1535507 is a prime.

It is a Duffinian number.

1535509 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1535507) 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, 1989 + ... + 2650.

It is an arithmetic number, because the mean of its divisors is an integer number (385120).

2^1535509 is an apocalyptic number.

It is an amenable number.

1535509 is a deficient number, since it is larger than the sum of its proper divisors (4971).

1535509 is an equidigital number, since it uses as much as digits as its factorization.

1535509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4970.

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

The square root of 1535509 is about 1239.1565679929. The cubic root of 1535509 is about 115.3676701383.

The spelling of 1535509 in words is "one million, five hundred thirty-five thousand, five hundred nine".