66405223 has 2 divisors, whose sum is σ = 66405224. Its totient is φ = 66405222.

The previous prime is 66405221. The next prime is 66405239. The reversal of 66405223 is 32250466.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66405223 - 2¹ = 66405221 is a prime.

Together with 66405221, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 66405191 and 66405200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66405221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33202611 + 33202612.

It is an arithmetic number, because the mean of its divisors is an integer number (33202612).

Almost surely, 2^66405223 is an apocalyptic number.

66405223 is a deficient number, since it is larger than the sum of its proper divisors (1).

66405223 is an equidigital number, since it uses as much as digits as its factorization.

66405223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 28.

The square root of 66405223 is about 8148.9399924162. The cubic root of 66405223 is about 404.9493875685.

Adding to 66405223 its reverse (32250466), we get a palindrome (98655689).

The spelling of 66405223 in words is "sixty-six million, four hundred five thousand, two hundred twenty-three".