1638340684 has 12 divisors (see below), whose sum is σ = 2914098208. Its totient is φ = 805741200.

The previous prime is 1638340681. The next prime is 1638340727. The reversal of 1638340684 is 4860438361.

It is a self number, because there is not a number n which added to its sum of digits gives 1638340684.

It is not an unprimeable number, because it can be changed into a prime (1638340681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3357012 + ... + 3357499.

Almost surely, 2^1638340684 is an apocalyptic number.

It is an amenable number.

1638340684 is a deficient number, since it is larger than the sum of its proper divisors (1275757524).

1638340684 is a wasteful number, since it uses less digits than its factorization.

1638340684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6714576 (or 6714574 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 43.

The square root of 1638340684 is about 40476.4213339075. The cubic root of 1638340684 is about 1178.8758526997.

The spelling of 1638340684 in words is "one billion, six hundred thirty-eight million, three hundred forty thousand, six hundred eighty-four".