6561604 has 12 divisors (see below), whose sum is σ = 13123264. Its totient is φ = 2812104.

The previous prime is 6561589. The next prime is 6561613. The reversal of 6561604 is 4061656.

6561604 is an admirable number.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 234343 = 6561604 / (6 + 5 + 6 + 1 + 6 + 0 + 4).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117144 + ... + 117199.

Almost surely, 2^6561604 is an apocalyptic number.

It is an amenable number.

6561604 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

6561604 is a wasteful number, since it uses less digits than its factorization.

6561604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234354 (or 234352 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 6561604 is about 2561.5628042271. The cubic root of 6561604 is about 187.2132886201.

The spelling of 6561604 in words is "six million, five hundred sixty-one thousand, six hundred four".