666403603 has 4 divisors (see below), whose sum is σ = 666523240. Its totient is φ = 666283968.

The previous prime is 666403561. The next prime is 666403651. The reversal of 666403603 is 306304666.

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 666403603 - 2⁹ = 666403091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666403693) 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, 51033 + ... + 62746.

It is an arithmetic number, because the mean of its divisors is an integer number (166630810).

Almost surely, 2^666403603 is an apocalyptic number.

666403603 is a deficient number, since it is larger than the sum of its proper divisors (119637).

666403603 is a wasteful number, since it uses less digits than its factorization.

666403603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119636.

The product of its (nonzero) digits is 46656, while the sum is 34.

The square root of 666403603 is about 25814.7942660793. The cubic root of 666403603 is about 873.4655459794.

The spelling of 666403603 in words is "six hundred sixty-six million, four hundred three thousand, six hundred three".