66455909 has 16 divisors (see below), whose sum is σ = 74640384. Its totient is φ = 58752000.

The previous prime is 66455903. The next prime is 66455911. The reversal of 66455909 is 90955466.

It is a cyclic number.

It is not a de Polignac number, because 66455909 - 2²⁰ = 65407333 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66455909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66455903) 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, 40709 + ... + 42309.

It is an arithmetic number, because the mean of its divisors is an integer number (4665024).

Almost surely, 2^66455909 is an apocalyptic number.

It is an amenable number.

66455909 is a deficient number, since it is larger than the sum of its proper divisors (8184475).

66455909 is a wasteful number, since it uses less digits than its factorization.

66455909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1748.

The product of its (nonzero) digits is 291600, while the sum is 44.

The square root of 66455909 is about 8152.0493742371. The cubic root of 66455909 is about 405.0523917387.

The spelling of 66455909 in words is "sixty-six million, four hundred fifty-five thousand, nine hundred nine".