663688840 has 32 divisors (see below), whose sum is σ = 1581142680. Its totient is φ = 249859072.

The previous prime is 663688807. The next prime is 663688859. The reversal of 663688840 is 48886366.

It can be written as a sum of positive squares in 4 ways, for example, as 588450564 + 75238276 = 24258^2 + 8674^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 487327 + ... + 488686.

Almost surely, 2^663688840 is an apocalyptic number.

It is an amenable number.

663688840 is an abundant number, since it is smaller than the sum of its proper divisors (917453840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

663688840 is a wasteful number, since it uses less digits than its factorization.

663688840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976041 (or 976037 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 49.

The square root of 663688840 is about 25762.1590710096. The cubic root of 663688840 is about 872.2778377064.

The spelling of 663688840 in words is "six hundred sixty-three million, six hundred eighty-eight thousand, eight hundred forty".