666310385 has 24 divisors (see below), whose sum is σ = 868329144. Its totient is φ = 490613760.

The previous prime is 666310369. The next prime is 666310387. The reversal of 666310385 is 583013666.

It can be written as a sum of positive squares in 12 ways, for example, as 664814656 + 1495729 = 25784^2 + 1223^2 .

It is not a de Polignac number, because 666310385 - 2⁴ = 666310369 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (666310387) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 354809 + ... + 356681.

It is an arithmetic number, because the mean of its divisors is an integer number (36180381).

Almost surely, 2^666310385 is an apocalyptic number.

666310385 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

666310385 is a deficient number, since it is larger than the sum of its proper divisors (202018759).

666310385 is a wasteful number, since it uses less digits than its factorization.

666310385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2325 (or 2312 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 666310385 is about 25812.9886878680. The cubic root of 666310385 is about 873.4248166538.

The spelling of 666310385 in words is "six hundred sixty-six million, three hundred ten thousand, three hundred eighty-five".