66430509 has 16 divisors (see below), whose sum is σ = 97863552. Its totient is φ = 39868928.

The previous prime is 66430499. The next prime is 66430513. The reversal of 66430509 is 90503466.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66430509 - 2⁵ = 66430477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66430509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66430589) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27144 + ... + 29489.

It is an arithmetic number, because the mean of its divisors is an integer number (6116472).

Almost surely, 2^66430509 is an apocalyptic number.

66430509 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

It is an amenable number.

66430509 is a deficient number, since it is larger than the sum of its proper divisors (31433043).

66430509 is a wasteful number, since it uses less digits than its factorization.

66430509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56676.

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 66430509 is about 8150.4913348828. The cubic root of 66430509 is about 405.0007803673. Note that the first 3 decimals are identical.

The spelling of 66430509 in words is "sixty-six million, four hundred thirty thousand, five hundred nine".