66513009 has 4 divisors (see below), whose sum is σ = 88684016. Its totient is φ = 44342004.

The previous prime is 66512989. The next prime is 66513017. The reversal of 66513009 is 90031566.

It is a happy number.

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.

It is not a de Polignac number, because 66513009 - 2⁷ = 66512881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66513049) 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, 11085499 + ... + 11085504.

It is an arithmetic number, because the mean of its divisors is an integer number (22171004).

Almost surely, 2^66513009 is an apocalyptic number.

It is an amenable number.

66513009 is a deficient number, since it is larger than the sum of its proper divisors (22171007).

66513009 is a wasteful number, since it uses less digits than its factorization.

66513009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22171006.

The product of its (nonzero) digits is 4860, while the sum is 30.

The square root of 66513009 is about 8155.5508091115. The cubic root of 66513009 is about 405.1683677341.

The spelling of 66513009 in words is "sixty-six million, five hundred thirteen thousand, nine".