663666111 has 24 divisors (see below), whose sum is σ = 1016102880. Its totient is φ = 415973376.

The previous prime is 663666103. The next prime is 663666119. The reversal of 663666111 is 111666366.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (663666103) and next prime (663666119).

It is not a de Polignac number, because 663666111 - 2³ = 663666103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663666119) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 197695 + ... + 201023.

It is an arithmetic number, because the mean of its divisors is an integer number (42337620).

Almost surely, 2^663666111 is an apocalyptic number.

663666111 is a deficient number, since it is larger than the sum of its proper divisors (352436769).

663666111 is a wasteful number, since it uses less digits than its factorization.

663666111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4655 (or 4652 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 663666111 is about 25761.7179357278. The cubic root of 663666111 is about 872.2678801138.

The spelling of 663666111 in words is "six hundred sixty-three million, six hundred sixty-six thousand, one hundred eleven".