665655541 has 8 divisors (see below), whose sum is σ = 687930264. Its totient is φ = 643668480.

The previous prime is 665655539. The next prime is 665655559. The reversal of 665655541 is 145556566.

It can be written as a sum of positive squares in 4 ways, for example, as 17189316 + 648466225 = 4146^2 + 25465^2 .

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 665655541 - 2¹ = 665655539 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 (665655841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67206 + ... + 76471.

It is an arithmetic number, because the mean of its divisors is an integer number (85991283).

Almost surely, 2^665655541 is an apocalyptic number.

It is an amenable number.

665655541 is a deficient number, since it is larger than the sum of its proper divisors (22274723).

665655541 is a wasteful number, since it uses less digits than its factorization.

665655541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143831.

The product of its digits is 540000, while the sum is 43.

The square root of 665655541 is about 25800.3011804126. The cubic root of 665655541 is about 873.1385914513.

The spelling of 665655541 in words is "six hundred sixty-five million, six hundred fifty-five thousand, five hundred forty-one".