66349909 has 2 divisors, whose sum is σ = 66349910. Its totient is φ = 66349908.

The previous prime is 66349897. The next prime is 66349937. The reversal of 66349909 is 90994366.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66096900 + 253009 = 8130^2 + 503^2 .

It is a cyclic number.

It is not a de Polignac number, because 66349909 - 2⁹ = 66349397 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 (66349939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33174954 + 33174955.

It is an arithmetic number, because the mean of its divisors is an integer number (33174955).

Almost surely, 2^66349909 is an apocalyptic number.

It is an amenable number.

66349909 is a deficient number, since it is larger than the sum of its proper divisors (1).

66349909 is an equidigital number, since it uses as much as digits as its factorization.

66349909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 314928, while the sum is 46.

The square root of 66349909 is about 8145.5453469980. The cubic root of 66349909 is about 404.8369185403.

The spelling of 66349909 in words is "sixty-six million, three hundred forty-nine thousand, nine hundred nine".