66623 has 4 divisors (see below), whose sum is σ = 70560.
Its totient is φ = 62688.
The previous prime is 66617. The next prime is 66629. The reversal of 66623 is 32666.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32666 = 2 ⋅16333.
It is an interprime number because it is at equal distance from previous prime (66617) and next prime (66629).
It is a cyclic number.
It is not a de Polignac number, because 66623 - 210 = 65599 is a prime.
It is a d-powerful number, because it can be written as 62 + 63 + 66 + 25 + 39 .
It is a Duffinian number.
It is a plaindrome in base 9.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (66629) 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, 1943 + ... + 1976.
It is an arithmetic number, because the mean of its divisors is an integer number (17640).
266623 is an apocalyptic number.
66623 is a deficient number, since it is larger than the sum of its proper divisors (3937).
66623 is a wasteful number, since it uses less digits than its factorization.
66623 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3936.
The product of its digits is 1296, while the sum is 23.
The square root of 66623 is about 258.1143157595.
The cubic root of 66623 is about 40.5391583873.
The spelling of 66623 in words is "sixty-six thousand, six hundred twenty-three".