659989949 has 2 divisors, whose sum is σ = 659989950. Its totient is φ = 659989948.

The previous prime is 659989903. The next prime is 659990011. The reversal of 659989949 is 949989956.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 400200025 + 259789924 = 20005^2 + 16118^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-659989949 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (659949949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 329994974 + 329994975.

It is an arithmetic number, because the mean of its divisors is an integer number (329994975).

Almost surely, 2^659989949 is an apocalyptic number.

It is an amenable number.

659989949 is a deficient number, since it is larger than the sum of its proper divisors (1).

659989949 is an equidigital number, since it uses as much as digits as its factorization.

659989949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56687040, while the sum is 68.

The square root of 659989949 is about 25690.2695392633. The cubic root of 659989949 is about 870.6543494024.

The spelling of 659989949 in words is "six hundred fifty-nine million, nine hundred eighty-nine thousand, nine hundred forty-nine".