665438057 has 4 divisors (see below), whose sum is σ = 674810496. Its totient is φ = 656065620.

The previous prime is 665438051. The next prime is 665438071. The reversal of 665438057 is 750834566.

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 665438057 - 2⁴ = 665438041 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665437999 and 665438017.

It is not an unprimeable number, because it can be changed into a prime (665438051) 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 3 ways as a sum of consecutive naturals, for example, 4686113 + ... + 4686254.

It is an arithmetic number, because the mean of its divisors is an integer number (168702624).

Almost surely, 2^665438057 is an apocalyptic number.

It is an amenable number.

665438057 is a deficient number, since it is larger than the sum of its proper divisors (9372439).

665438057 is an equidigital number, since it uses as much as digits as its factorization.

665438057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9372438.

The product of its (nonzero) digits is 604800, while the sum is 44.

The square root of 665438057 is about 25796.0860790935. The cubic root of 665438057 is about 873.0434900331.

The spelling of 665438057 in words is "six hundred sixty-five million, four hundred thirty-eight thousand, fifty-seven".