663221816 has 16 divisors (see below), whose sum is σ = 1316690640. Its totient is φ = 312104320.

The previous prime is 663221803. The next prime is 663221821. The reversal of 663221816 is 618122366.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2438180 + ... + 2438451.

It is an arithmetic number, because the mean of its divisors is an integer number (82293165).

Almost surely, 2^663221816 is an apocalyptic number.

It is an amenable number.

663221816 is a deficient number, since it is larger than the sum of its proper divisors (653468824).

663221816 is a wasteful number, since it uses less digits than its factorization.

663221816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4876654 (or 4876650 counting only the distinct ones).

The product of its digits is 20736, while the sum is 35.

The square root of 663221816 is about 25753.0933287634. The cubic root of 663221816 is about 872.0731884534.

The spelling of 663221816 in words is "six hundred sixty-three million, two hundred twenty-one thousand, eight hundred sixteen".