666385403 has 4 divisors (see below), whose sum is σ = 689364240. Its totient is φ = 643406568.

The previous prime is 666385381. The next prime is 666385469. The reversal of 666385403 is 304583666.

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 666385403 - 2¹⁰ = 666384379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666385103) 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, 11489375 + ... + 11489432.

It is an arithmetic number, because the mean of its divisors is an integer number (172341060).

Almost surely, 2^666385403 is an apocalyptic number.

666385403 is a deficient number, since it is larger than the sum of its proper divisors (22978837).

666385403 is a wasteful number, since it uses less digits than its factorization.

666385403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22978836.

The product of its (nonzero) digits is 311040, while the sum is 41.

The square root of 666385403 is about 25814.4417526314. The cubic root of 666385403 is about 873.4575942329.

The spelling of 666385403 in words is "six hundred sixty-six million, three hundred eighty-five thousand, four hundred three".