665600506 has 4 divisors (see below), whose sum is σ = 998400762. Its totient is φ = 332800252.

The previous prime is 665600501. The next prime is 665600521. The reversal of 665600506 is 605006566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 524822281 + 140778225 = 22909^2 + 11865^2 .

It is not an unprimeable number, because it can be changed into a prime (665600501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166400125 + ... + 166400128.

Almost surely, 2^665600506 is an apocalyptic number.

665600506 is a deficient number, since it is larger than the sum of its proper divisors (332800256).

665600506 is a wasteful number, since it uses less digits than its factorization.

665600506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332800255.

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 665600506 is about 25799.2346010497. The cubic root of 665600506 is about 873.1145277008.

The spelling of 665600506 in words is "six hundred sixty-five million, six hundred thousand, five hundred six".