1643406368 has 96 divisors (see below), whose sum is σ = 3514775040. Its totient is φ = 753960960.

The previous prime is 1643406367. The next prime is 1643406383. The reversal of 1643406368 is 8636043461.

It is not an unprimeable number, because it can be changed into a prime (1643406367) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2707121 + ... + 2707727.

It is an arithmetic number, because the mean of its divisors is an integer number (36612240).

Almost surely, 2^1643406368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643406368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1757387520).

1643406368 is an abundant number, since it is smaller than the sum of its proper divisors (1871368672).

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

1643406368 is a wasteful number, since it uses less digits than its factorization.

1643406368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770 (or 762 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 41.

The square root of 1643406368 is about 40538.9487776879. The cubic root of 1643406368 is about 1180.0896149502.

The spelling of 1643406368 in words is "one billion, six hundred forty-three million, four hundred six thousand, three hundred sixty-eight".