66560399 has 4 divisors (see below), whose sum is σ = 66658536. Its totient is φ = 66462264.

The previous prime is 66560369. The next prime is 66560407. The reversal of 66560399 is 99306566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66560399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66560309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48044 + ... + 49409.

It is an arithmetic number, because the mean of its divisors is an integer number (16664634).

Almost surely, 2^66560399 is an apocalyptic number.

66560399 is a deficient number, since it is larger than the sum of its proper divisors (98137).

66560399 is an equidigital number, since it uses as much as digits as its factorization.

66560399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98136.

The product of its (nonzero) digits is 262440, while the sum is 44.

The square root of 66560399 is about 8158.4556749424. The cubic root of 66560399 is about 405.2645713233.

The spelling of 66560399 in words is "sixty-six million, five hundred sixty thousand, three hundred ninety-nine".