1643854216 has 16 divisors (see below), whose sum is σ = 3091063500. Its totient is φ = 819570624.

The previous prime is 1643854211. The next prime is 1643854301. The reversal of 1643854216 is 6124583461.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1285509316 + 358344900 = 35854^2 + 18930^2 .

It is not an unprimeable number, because it can be changed into a prime (1643854211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 291595 + ... + 297178.

Almost surely, 2^1643854216 is an apocalyptic number.

It is an amenable number.

1643854216 is a deficient number, since it is larger than the sum of its proper divisors (1447209284).

1643854216 is a wasteful number, since it uses less digits than its factorization.

1643854216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589128 (or 589124 counting only the distinct ones).

The product of its digits is 138240, while the sum is 40.

The square root of 1643854216 is about 40544.4720769675. The cubic root of 1643854216 is about 1180.1968014185.

The spelling of 1643854216 in words is "one billion, six hundred forty-three million, eight hundred fifty-four thousand, two hundred sixteen".