6561556 has 12 divisors (see below), whose sum is σ = 11515392. Its totient is φ = 3271448.

The previous prime is 6561551. The next prime is 6561557. The reversal of 6561556 is 6551656.

It is a super-2 number, since 2×6561556² = 86108034282272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561551) 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, 610 + ... + 3673.

It is an arithmetic number, because the mean of its divisors is an integer number (959616).

Almost surely, 2^6561556 is an apocalyptic number.

It is an amenable number.

6561556 is a deficient number, since it is larger than the sum of its proper divisors (4953836).

6561556 is a wasteful number, since it uses less digits than its factorization.

6561556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4670 (or 4668 counting only the distinct ones).

The product of its digits is 27000, while the sum is 34.

The square root of 6561556 is about 2561.5534349297. The cubic root of 6561556 is about 187.2128321128.

It can be divided in two parts, 6561 and 556, that added together give a palindrome (7117).

The spelling of 6561556 in words is "six million, five hundred sixty-one thousand, five hundred fifty-six".