12757561 has 4 divisors (see below), whose sum is σ = 12764752. Its totient is φ = 12750372.

The previous prime is 12757543. The next prime is 12757583. The reversal of 12757561 is 16575721.

It is a happy number.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 12757561 - 2⁹ = 12757049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12757501) 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 3 ways as a sum of consecutive naturals, for example, 1186 + ... + 5188.

It is an arithmetic number, because the mean of its divisors is an integer number (3191188).

Almost surely, 2^12757561 is an apocalyptic number.

It is an amenable number.

12757561 is a deficient number, since it is larger than the sum of its proper divisors (7191).

12757561 is an equidigital number, since it uses as much as digits as its factorization.

12757561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7190.

The product of its digits is 14700, while the sum is 34.

The square root of 12757561 is about 3571.7728091243. The cubic root of 12757561 is about 233.6626070014.

It can be divided in two parts, 1275 and 7561, that added together give a square (8836 = 94²).

The spelling of 12757561 in words is "twelve million, seven hundred fifty-seven thousand, five hundred sixty-one".