666403563 has 8 divisors (see below), whose sum is σ = 1015472128. Its totient is φ = 380802024.

The previous prime is 666403561. The next prime is 666403651. The reversal of 666403563 is 365304666.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 666403563 - 2¹ = 666403561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666403561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15866731 + ... + 15866772.

It is an arithmetic number, because the mean of its divisors is an integer number (126934016).

Almost surely, 2^666403563 is an apocalyptic number.

666403563 is a deficient number, since it is larger than the sum of its proper divisors (349068565).

666403563 is a wasteful number, since it uses less digits than its factorization.

666403563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31733513.

The product of its (nonzero) digits is 233280, while the sum is 39.

The square root of 666403563 is about 25814.7934913297. The cubic root of 666403563 is about 873.4655285032.

The spelling of 666403563 in words is "six hundred sixty-six million, four hundred three thousand, five hundred sixty-three".