666614989 has 2 divisors, whose sum is σ = 666614990. Its totient is φ = 666614988.

The previous prime is 666614987. The next prime is 666615013. The reversal of 666614989 is 989416666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 516062089 + 150552900 = 22717^2 + 12270^2 .

It is a cyclic number.

It is not a de Polignac number, because 666614989 - 2¹ = 666614987 is a prime.

Together with 666614987, it forms a pair of twin primes.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666614983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333307494 + 333307495.

It is an arithmetic number, because the mean of its divisors is an integer number (333307495).

Almost surely, 2^666614989 is an apocalyptic number.

It is an amenable number.

666614989 is a deficient number, since it is larger than the sum of its proper divisors (1).

666614989 is an equidigital number, since it uses as much as digits as its factorization.

666614989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3359232, while the sum is 55.

The square root of 666614989 is about 25818.8882216102. Note that the first 3 decimals coincide. The cubic root of 666614989 is about 873.5578918530.

The spelling of 666614989 in words is "six hundred sixty-six million, six hundred fourteen thousand, nine hundred eighty-nine".