666115563 has 4 divisors (see below), whose sum is σ = 888154088. Its totient is φ = 444077040.

The previous prime is 666115531. The next prime is 666115579. The reversal of 666115563 is 365511666.

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

It is not a de Polignac number, because 666115563 - 2⁵ = 666115531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666115363) 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, 111019258 + ... + 111019263.

It is an arithmetic number, because the mean of its divisors is an integer number (222038522).

Almost surely, 2^666115563 is an apocalyptic number.

666115563 is a deficient number, since it is larger than the sum of its proper divisors (222038525).

666115563 is a wasteful number, since it uses less digits than its factorization.

666115563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222038524.

The product of its digits is 97200, while the sum is 39.

The square root of 666115563 is about 25809.2146916562. The cubic root of 666115563 is about 873.3396816773.

The spelling of 666115563 in words is "six hundred sixty-six million, one hundred fifteen thousand, five hundred sixty-three".