666505563 has 8 divisors (see below), whose sum is σ = 888803088. Its totient is φ = 444272544.

The previous prime is 666505561. The next prime is 666505571. The reversal of 666505563 is 365505666.

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

It is not a de Polignac number, because 666505563 - 2¹ = 666505561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666505561) 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, 18781 + ... + 41057.

It is an arithmetic number, because the mean of its divisors is an integer number (111100386).

Almost surely, 2^666505563 is an apocalyptic number.

666505563 is a deficient number, since it is larger than the sum of its proper divisors (222297525).

666505563 is a wasteful number, since it uses less digits than its factorization.

666505563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32253.

The product of its (nonzero) digits is 486000, while the sum is 42.

The square root of 666505563 is about 25816.7690271265. The cubic root of 666505563 is about 873.5100905592.

The spelling of 666505563 in words is "six hundred sixty-six million, five hundred five thousand, five hundred sixty-three".