6561100 has 108 divisors (see below), whose sum is σ = 18009264. Its totient is φ = 2056320.

The previous prime is 6561097. The next prime is 6561103. The reversal of 6561100 is 11656.

It is an interprime number because it is at equal distance from previous prime (6561097) and next prime (6561103).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561103) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 63649 + ... + 63751.

Almost surely, 2^6561100 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6561100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9004632).

6561100 is an abundant number, since it is smaller than the sum of its proper divisors (11448164).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6561100 is a wasteful number, since it uses less digits than its factorization.

6561100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 6561100 is about 2561.4644248945. The cubic root of 6561100 is about 187.2084951827.

Adding to 6561100 its reverse (11656), we get a palindrome (6572756).

The spelling of 6561100 in words is "six million, five hundred sixty-one thousand, one hundred".