6561523 has 4 divisors (see below), whose sum is σ = 6567880. Its totient is φ = 6555168.

The previous prime is 6561521. The next prime is 6561539. The reversal of 6561523 is 3251656.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 6561523 - 2¹ = 6561521 is a prime.

It is a super-4 number, since 4×6561523⁴ (a number of 28 digits) contains 4444 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6561491 and 6561500.

It is not an unprimeable number, because it can be changed into a prime (6561521) 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, 1233 + ... + 3826.

It is an arithmetic number, because the mean of its divisors is an integer number (1641970).

Almost surely, 2^6561523 is an apocalyptic number.

6561523 is a deficient number, since it is larger than the sum of its proper divisors (6357).

6561523 is a wasteful number, since it uses less digits than its factorization.

6561523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6356.

The product of its digits is 5400, while the sum is 28.

The square root of 6561523 is about 2561.5469935178. The cubic root of 6561523 is about 187.2125182628.

The spelling of 6561523 in words is "six million, five hundred sixty-one thousand, five hundred twenty-three".