665611061 has 8 divisors (see below), whose sum is σ = 681436800. Its totient is φ = 649801152.

The previous prime is 665611057. The next prime is 665611073. The reversal of 665611061 is 160116566.

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 665611061 - 2² = 665611057 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 (665511061) 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, 162365 + ... + 166413.

It is an arithmetic number, because the mean of its divisors is an integer number (85179600).

Almost surely, 2^665611061 is an apocalyptic number.

It is an amenable number.

665611061 is a deficient number, since it is larger than the sum of its proper divisors (15825739).

665611061 is a wasteful number, since it uses less digits than its factorization.

665611061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7915.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 665611061 is about 25799.4391605709. The cubic root of 665611061 is about 873.1191429192.

The spelling of 665611061 in words is "six hundred sixty-five million, six hundred eleven thousand, sixty-one".