665520223 has 2 divisors, whose sum is σ = 665520224. Its totient is φ = 665520222.

The previous prime is 665520197. The next prime is 665520337. The reversal of 665520223 is 322025566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665520223 - 2⁹ = 665519711 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (665521223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332760111 + 332760112.

It is an arithmetic number, because the mean of its divisors is an integer number (332760112).

Almost surely, 2^665520223 is an apocalyptic number.

665520223 is a deficient number, since it is larger than the sum of its proper divisors (1).

665520223 is an equidigital number, since it uses as much as digits as its factorization.

665520223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 665520223 is about 25797.6786358773. The cubic root of 665520223 is about 873.0794220223.

Adding to 665520223 its reverse (322025566), we get a palindrome (987545789).

The spelling of 665520223 in words is "six hundred sixty-five million, five hundred twenty thousand, two hundred twenty-three".