666776305 has 16 divisors (see below), whose sum is σ = 877942800. Its totient is φ = 483095808.

The previous prime is 666776293. The next prime is 666776309. The reversal of 666776305 is 503677666.

It can be written as a sum of positive squares in 8 ways, for example, as 516961 + 666259344 = 719^2 + 25812^2 .

It is not a de Polignac number, because 666776305 - 2¹⁵ = 666743537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666776309) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93330 + ... + 100219.

It is an arithmetic number, because the mean of its divisors is an integer number (54871425).

Almost surely, 2^666776305 is an apocalyptic number.

666776305 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

666776305 is a deficient number, since it is larger than the sum of its proper divisors (211166495).

666776305 is a wasteful number, since it uses less digits than its factorization.

666776305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193620.

The product of its (nonzero) digits is 952560, while the sum is 46.

The square root of 666776305 is about 25822.0120246274. The cubic root of 666776305 is about 873.6283510644.

The spelling of 666776305 in words is "six hundred sixty-six million, seven hundred seventy-six thousand, three hundred five".