665056111 has 4 divisors (see below), whose sum is σ = 665450632. Its totient is φ = 664661592.

The previous prime is 665056097. The next prime is 665056127. The reversal of 665056111 is 111650566.

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 665056111 - 2⁷ = 665055983 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 (665056151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194721 + ... + 198106.

It is an arithmetic number, because the mean of its divisors is an integer number (166362658).

Almost surely, 2^665056111 is an apocalyptic number.

665056111 is a deficient number, since it is larger than the sum of its proper divisors (394521).

665056111 is a wasteful number, since it uses less digits than its factorization.

665056111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394520.

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 665056111 is about 25788.6818391325. The cubic root of 665056111 is about 872.8764224981.

The spelling of 665056111 in words is "six hundred sixty-five million, fifty-six thousand, one hundred eleven".