66841009 has 4 divisors (see below), whose sum is σ = 67838704. Its totient is φ = 65843316.

The previous prime is 66841007. The next prime is 66841037. The reversal of 66841009 is 90014866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90014866 = 2 ⋅45007433.

It is a cyclic number.

It is not a de Polignac number, because 66841009 - 2¹ = 66841007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66841001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 498747 + ... + 498880.

It is an arithmetic number, because the mean of its divisors is an integer number (16959676).

Almost surely, 2^66841009 is an apocalyptic number.

It is an amenable number.

66841009 is a deficient number, since it is larger than the sum of its proper divisors (997695).

66841009 is an equidigital number, since it uses as much as digits as its factorization.

66841009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 997694.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 66841009 is about 8175.6350823652. The cubic root of 66841009 is about 405.8332871309.

The spelling of 66841009 in words is "sixty-six million, eight hundred forty-one thousand, nine".