663607816 has 8 divisors (see below), whose sum is σ = 1244264670. Its totient is φ = 331803904.

The previous prime is 663607807. The next prime is 663607831. The reversal of 663607816 is 618706366.

It can be written as a sum of positive squares in only one way, i.e., 374267716 + 289340100 = 19346^2 + 17010^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41475481 + ... + 41475496.

Almost surely, 2^663607816 is an apocalyptic number.

It is an amenable number.

663607816 is a deficient number, since it is larger than the sum of its proper divisors (580656854).

663607816 is a wasteful number, since it uses less digits than its factorization.

663607816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82950983 (or 82950979 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 663607816 is about 25760.5864840069. The cubic root of 663607816 is about 872.2423399894.

The spelling of 663607816 in words is "six hundred sixty-three million, six hundred seven thousand, eight hundred sixteen".