666015999 has 8 divisors (see below), whose sum is σ = 968750592. Its totient is φ = 403646040.

The previous prime is 666015941. The next prime is 666016007. The reversal of 666015999 is 999510666.

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

It is not a de Polignac number, because 666015999 - 2¹⁹ = 665491711 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666015929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10091119 + ... + 10091184.

It is an arithmetic number, because the mean of its divisors is an integer number (121093824).

Almost surely, 2^666015999 is an apocalyptic number.

666015999 is a deficient number, since it is larger than the sum of its proper divisors (302734593).

666015999 is a wasteful number, since it uses less digits than its factorization.

666015999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20182317.

The product of its (nonzero) digits is 787320, while the sum is 51.

The square root of 666015999 is about 25807.2857735950. The cubic root of 666015999 is about 873.2961669432.

The spelling of 666015999 in words is "six hundred sixty-six million, fifteen thousand, nine hundred ninety-nine".