665438056 has 16 divisors (see below), whose sum is σ = 1248439140. Its totient is φ = 332520960.

The previous prime is 665438051. The next prime is 665438071. The reversal of 665438056 is 650834566.

It can be written as a sum of positive squares in 2 ways, for example, as 614544100 + 50893956 = 24790^2 + 7134^2 .

It is not an unprimeable number, because it can be changed into a prime (665438051) 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, 9961 + ... + 37816.

Almost surely, 2^665438056 is an apocalyptic number.

It is an amenable number.

665438056 is a deficient number, since it is larger than the sum of its proper divisors (583001084).

665438056 is a wasteful number, since it uses less digits than its factorization.

665438056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49524 (or 49520 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 43.

The square root of 665438056 is about 25796.0860597107. The cubic root of 665438056 is about 873.0434895958.

The spelling of 665438056 in words is "six hundred sixty-five million, four hundred thirty-eight thousand, fifty-six".