6561799 has 4 divisors (see below), whose sum is σ = 6570720. Its totient is φ = 6552880.

The previous prime is 6561791. The next prime is 6561809. The reversal of 6561799 is 9971656.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6561799 - 2³ = 6561791 is a prime.

It is a super-2 number, since 2×6561799² = 86114412232802, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3247 + ... + 4864.

It is an arithmetic number, because the mean of its divisors is an integer number (1642680).

Almost surely, 2^6561799 is an apocalyptic number.

6561799 is a deficient number, since it is larger than the sum of its proper divisors (8921).

6561799 is an equidigital number, since it uses as much as digits as its factorization.

6561799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8920.

The product of its digits is 102060, while the sum is 43.

The square root of 6561799 is about 2561.6008666457. The cubic root of 6561799 is about 187.2151431580.

The spelling of 6561799 in words is "six million, five hundred sixty-one thousand, seven hundred ninety-nine".