1535561 has 4 divisors (see below), whose sum is σ = 1616400. Its totient is φ = 1454724.

The previous prime is 1535543. The next prime is 1535563. The reversal of 1535561 is 1655351.

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: 1655351 = 139 ⋅11909.

It is a cyclic number.

It is not a de Polignac number, because 1535561 - 2⁶ = 1535497 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1535561.

It is not an unprimeable number, because it can be changed into a prime (1535563) 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, 40391 + ... + 40428.

It is an arithmetic number, because the mean of its divisors is an integer number (404100).

2^1535561 is an apocalyptic number.

It is an amenable number.

1535561 is a deficient number, since it is larger than the sum of its proper divisors (80839).

1535561 is an equidigital number, since it uses as much as digits as its factorization.

1535561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80838.

The product of its digits is 2250, while the sum is 26.

The square root of 1535561 is about 1239.1775498289. The cubic root of 1535561 is about 115.3689724321.

The spelling of 1535561 in words is "one million, five hundred thirty-five thousand, five hundred sixty-one".