66780223 has 4 divisors (see below), whose sum is σ = 67584888. Its totient is φ = 65975560.

The previous prime is 66780211. The next prime is 66780251. The reversal of 66780223 is 32208766.

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

It is a cyclic number.

It is not a de Polignac number, because 66780223 - 2⁹ = 66779711 is a prime.

It is a Duffinian number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66780253) 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, 402208 + ... + 402373.

It is an arithmetic number, because the mean of its divisors is an integer number (16896222).

Almost surely, 2^66780223 is an apocalyptic number.

66780223 is a deficient number, since it is larger than the sum of its proper divisors (804665).

66780223 is an equidigital number, since it uses as much as digits as its factorization.

66780223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804664.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 66780223 is about 8171.9167274269. The cubic root of 66780223 is about 405.7102266304.

Adding to 66780223 its reverse (32208766), we get a palindrome (98988989).

The spelling of 66780223 in words is "sixty-six million, seven hundred eighty thousand, two hundred twenty-three".