66599 has 8 divisors (see below), whose sum is σ = 73920. Its totient is φ = 59616.

The previous prime is 66593. The next prime is 66601. The reversal of 66599 is 99566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66599 - 2⁸ = 66343 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66593) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 557 + ... + 665.

It is an arithmetic number, because the mean of its divisors is an integer number (9240).

2⁶⁶⁵⁹⁹ is an apocalyptic number.

66599 is a deficient number, since it is larger than the sum of its proper divisors (7321).

66599 is a wasteful number, since it uses less digits than its factorization.

66599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169.

The product of its digits is 14580, while the sum is 35.

The square root of 66599 is about 258.0678205434. The cubic root of 66599 is about 40.5342899152.

Subtracting from 66599 its sum of digits (35), we obtain a square (66564 = 258²).

The spelling of 66599 in words is "sixty-six thousand, five hundred ninety-nine".