663686836 has 6 divisors (see below), whose sum is σ = 1161451970. Its totient is φ = 331843416.

The previous prime is 663686831. The next prime is 663686861. The reversal of 663686836 is 638686366.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 357436836 + 306250000 = 18906^2 + 17500^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663686831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82960851 + ... + 82960858.

Almost surely, 2^663686836 is an apocalyptic number.

It is an amenable number.

663686836 is a deficient number, since it is larger than the sum of its proper divisors (497765134).

663686836 is a wasteful number, since it uses less digits than its factorization.

663686836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165921713 (or 165921711 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 52.

The square root of 663686836 is about 25762.1201767246. The cubic root of 663686836 is about 872.2769597616.

The spelling of 663686836 in words is "six hundred sixty-three million, six hundred eighty-six thousand, eight hundred thirty-six".