666401713 has 2 divisors, whose sum is σ = 666401714. Its totient is φ = 666401712.

The previous prime is 666401711. The next prime is 666401719. The reversal of 666401713 is 317104666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 625850289 + 40551424 = 25017^2 + 6368^2 .

It is a cyclic number.

It is not a de Polignac number, because 666401713 - 2¹ = 666401711 is a prime.

Together with 666401711, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (666401711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333200856 + 333200857.

It is an arithmetic number, because the mean of its divisors is an integer number (333200857).

Almost surely, 2^666401713 is an apocalyptic number.

It is an amenable number.

666401713 is a deficient number, since it is larger than the sum of its proper divisors (1).

666401713 is an equidigital number, since it uses as much as digits as its factorization.

666401713 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 666401713 is about 25814.7576591375. The cubic root of 666401713 is about 873.4647202278.

The spelling of 666401713 in words is "six hundred sixty-six million, four hundred one thousand, seven hundred thirteen".