6555561 has 4 divisors (see below), whose sum is σ = 8740752. Its totient is φ = 4370372.

The previous prime is 6555547. The next prime is 6555581. The reversal of 6555561 is 1655556.

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.

It is a cyclic number.

It is not a de Polignac number, because 6555561 - 2⁷ = 6555433 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (6555541) 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, 1092591 + ... + 1092596.

It is an arithmetic number, because the mean of its divisors is an integer number (2185188).

Almost surely, 2^6555561 is an apocalyptic number.

It is an amenable number.

6555561 is a deficient number, since it is larger than the sum of its proper divisors (2185191).

6555561 is a wasteful number, since it uses less digits than its factorization.

6555561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2185190.

The product of its digits is 22500, while the sum is 33.

The square root of 6555561 is about 2560.3829791654. The cubic root of 6555561 is about 187.1557987448.

It can be divided in two parts, 655 and 5561, that added together give a triangular number (6216 = T₁₁₁).

The spelling of 6555561 in words is "six million, five hundred fifty-five thousand, five hundred sixty-one".