66390 has 16 divisors (see below), whose sum is σ = 159408. Its totient is φ = 17696.

The previous prime is 66383. The next prime is 66403. The reversal of 66390 is 9366.

It is a self number, because there is not a number n which added to its sum of digits gives 66390.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1077 + ... + 1136.

It is an arithmetic number, because the mean of its divisors is an integer number (9963).

2⁶⁶³⁹⁰ is an apocalyptic number.

66390 is an abundant number, since it is smaller than the sum of its proper divisors (93018).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79704).

66390 is a wasteful number, since it uses less digits than its factorization.

66390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2223.

The product of its (nonzero) digits is 972, while the sum is 24.

The square root of 66390 is about 257.6625700407. The cubic root of 66390 is about 40.4918441129.

Subtracting from 66390 its sum of digits (24), we obtain a palindrome (66366).

The spelling of 66390 in words is "sixty-six thousand, three hundred ninety".