665134123 has 4 divisors (see below), whose sum is σ = 665365680. Its totient is φ = 664902568.

The previous prime is 665134117. The next prime is 665134133. The reversal of 665134123 is 321431566.

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 665134123 - 2⁵ = 665134091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665134133) 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, 111415 + ... + 117232.

It is an arithmetic number, because the mean of its divisors is an integer number (166341420).

Almost surely, 2^665134123 is an apocalyptic number.

665134123 is a deficient number, since it is larger than the sum of its proper divisors (231557).

665134123 is a wasteful number, since it uses less digits than its factorization.

665134123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231556.

The product of its digits is 12960, while the sum is 31.

The square root of 665134123 is about 25790.1943187716. The cubic root of 665134123 is about 872.9105510335.

Adding to 665134123 its reverse (321431566), we get a palindrome (986565689).

The spelling of 665134123 in words is "six hundred sixty-five million, one hundred thirty-four thousand, one hundred twenty-three".