666672613 has 2 divisors, whose sum is σ = 666672614. Its totient is φ = 666672612.

The previous prime is 666672607. The next prime is 666672631. The reversal of 666672613 is 316276666.

666672613 = 18257² + 18258².

Together with next prime (666672631) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 333354564 + 333318049 = 18258^2 + 18257^2 .

It is a cyclic number.

It is not a de Polignac number, because 666672613 - 2²⁹ = 129801701 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666672613.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666672673) 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 as a sum of consecutive naturals, namely, 333336306 + 333336307.

It is an arithmetic number, because the mean of its divisors is an integer number (333336307).

Almost surely, 2^666672613 is an apocalyptic number.

666672613 is the 18258-th centered square number.

It is an amenable number.

666672613 is a deficient number, since it is larger than the sum of its proper divisors (1).

666672613 is an equidigital number, since it uses as much as digits as its factorization.

666672613 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 43.

The square root of 666672613 is about 25820.0041247092. The cubic root of 666672613 is about 873.5830620289.

The spelling of 666672613 in words is "six hundred sixty-six million, six hundred seventy-two thousand, six hundred thirteen".