6661559 has 8 divisors (see below), whose sum is σ = 7176192. Its totient is φ = 6165720.

The previous prime is 6661553. The next prime is 6661583. The reversal of 6661559 is 9551666.

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

It is a cyclic number.

It is not a de Polignac number, because 6661559 - 2²⁰ = 5612983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661553) 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, 3959 + ... + 5384.

It is an arithmetic number, because the mean of its divisors is an integer number (897024).

Almost surely, 2^6661559 is an apocalyptic number.

6661559 is a deficient number, since it is larger than the sum of its proper divisors (514633).

6661559 is a wasteful number, since it uses less digits than its factorization.

6661559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9397.

The product of its digits is 48600, while the sum is 38.

The square root of 6661559 is about 2580.9996125532. Note that the first 3 decimals coincide. The cubic root of 6661559 is about 188.1591285124.

The spelling of 6661559 in words is "six million, six hundred sixty-one thousand, five hundred fifty-nine".