6561669 has 8 divisors (see below), whose sum is σ = 9209440. Its totient is φ = 4144176.

The previous prime is 6561649. The next prime is 6561673. The reversal of 6561669 is 9661656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6561669 - 2⁵ = 6561637 is a prime.

It is a super-2 number, since 2×6561669² = 86111000131122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561619) 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 7 ways as a sum of consecutive naturals, for example, 57502 + ... + 57615.

It is an arithmetic number, because the mean of its divisors is an integer number (1151180).

Almost surely, 2^6561669 is an apocalyptic number.

It is an amenable number.

6561669 is a deficient number, since it is larger than the sum of its proper divisors (2647771).

6561669 is a wasteful number, since it uses less digits than its factorization.

6561669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115139.

The product of its digits is 58320, while the sum is 39.

The square root of 6561669 is about 2561.5754917628. The cubic root of 6561669 is about 187.2139068034.

The spelling of 6561669 in words is "six million, five hundred sixty-one thousand, six hundred sixty-nine".