666744377 has 6 divisors (see below), whose sum is σ = 721977822. Its totient is φ = 615456192.

The previous prime is 666744361. The next prime is 666744413. The reversal of 666744377 is 773447666.

It can be written as a sum of positive squares in 3 ways, for example, as 4145296 + 662599081 = 2036^2 + 25741^2 .

It is not a de Polignac number, because 666744377 - 2⁴ = 666744361 is a prime.

It is a super-2 number, since 2×666744377² = 889096128522236258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666744347) 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 5 ways as a sum of consecutive naturals, for example, 1972448 + ... + 1972785.

It is an arithmetic number, because the mean of its divisors is an integer number (120329637).

Almost surely, 2^666744377 is an apocalyptic number.

It is an amenable number.

666744377 is a deficient number, since it is larger than the sum of its proper divisors (55233445).

666744377 is a wasteful number, since it uses less digits than its factorization.

666744377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3945259 (or 3945246 counting only the distinct ones).

The product of its digits is 3556224, while the sum is 50.

The square root of 666744377 is about 25821.3937849993. The cubic root of 666744377 is about 873.6144065321.

The spelling of 666744377 in words is "six hundred sixty-six million, seven hundred forty-four thousand, three hundred seventy-seven".