1646678216 has 16 divisors (see below), whose sum is σ = 3094658700. Its totient is φ = 821435904.

The previous prime is 1646678207. The next prime is 1646678239. The reversal of 1646678216 is 6128766461.

It can be written as a sum of positive squares in 2 ways, for example, as 1628445316 + 18232900 = 40354^2 + 4270^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234221 + ... + 241148.

Almost surely, 2^1646678216 is an apocalyptic number.

It is an amenable number.

1646678216 is a deficient number, since it is larger than the sum of its proper divisors (1447980484).

1646678216 is a wasteful number, since it uses less digits than its factorization.

1646678216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475808 (or 475804 counting only the distinct ones).

The product of its digits is 580608, while the sum is 47.

The square root of 1646678216 is about 40579.2830887881. The cubic root of 1646678216 is about 1180.8722402790.

The spelling of 1646678216 in words is "one billion, six hundred forty-six million, six hundred seventy-eight thousand, two hundred sixteen".