66289209 has 20 divisors (see below), whose sum is σ = 103121616. Its totient is φ = 37875432.

The previous prime is 66289193. The next prime is 66289213. The reversal of 66289209 is 90298266.

It is not a de Polignac number, because 66289209 - 2⁴ = 66289193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66289109) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2602 + ... + 11804.

Almost surely, 2^66289209 is an apocalyptic number.

It is an amenable number.

66289209 is a deficient number, since it is larger than the sum of its proper divisors (36832407).

66289209 is an frugal number, since it uses more digits than its factorization.

66289209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9234 (or 9213 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 42.

The square root of 66289209 is about 8141.8185315076. The cubic root of 66289209 is about 404.7134262913.

The spelling of 66289209 in words is "sixty-six million, two hundred eighty-nine thousand, two hundred nine".