665166061061 has 4 divisors (see below), whose sum is σ = 665168115072. Its totient is φ = 665164007052.

The previous prime is 665166061031. The next prime is 665166061073. The reversal of 665166061061 is 160160661566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 665166061061 - 2¹⁰ = 665166060037 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 (665166061031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 422735 + ... + 1228428.

It is an arithmetic number, because the mean of its divisors is an integer number (166292028768).

Almost surely, 2^665166061061 is an apocalyptic number.

It is an amenable number.

665166061061 is a deficient number, since it is larger than the sum of its proper divisors (2054011).

665166061061 is a wasteful number, since it uses less digits than its factorization.

665166061061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2054010.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 665166061061 in words is "six hundred sixty-five billion, one hundred sixty-six million, sixty-one thousand, sixty-one".