6561771 has 8 divisors (see below), whose sum is σ = 8914320. Its totient is φ = 4291872.

The previous prime is 6561767. The next prime is 6561781. The reversal of 6561771 is 1771656.

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

It is not a de Polignac number, because 6561771 - 2² = 6561767 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (6561721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20476 + ... + 20793.

It is an arithmetic number, because the mean of its divisors is an integer number (1114290).

Almost surely, 2^6561771 is an apocalyptic number.

6561771 is a deficient number, since it is larger than the sum of its proper divisors (2352549).

6561771 is a wasteful number, since it uses less digits than its factorization.

6561771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41325.

The product of its digits is 8820, while the sum is 33.

The square root of 6561771 is about 2561.5954013076. The cubic root of 6561771 is about 187.2148768676.

The spelling of 6561771 in words is "six million, five hundred sixty-one thousand, seven hundred seventy-one".