1643431344 has 40 divisors (see below), whose sum is σ = 4495270320. Its totient is φ = 515586048.

The previous prime is 1643431337. The next prime is 1643431373. The reversal of 1643431344 is 4431343461.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

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, 1006189 + ... + 1007820.

It is an arithmetic number, because the mean of its divisors is an integer number (112381758).

Almost surely, 2^1643431344 is an apocalyptic number.

It is an amenable number.

1643431344 is an abundant number, since it is smaller than the sum of its proper divisors (2851838976).

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

1643431344 is a wasteful number, since it uses less digits than its factorization.

1643431344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2014037 (or 2014031 counting only the distinct ones).

The product of its digits is 41472, while the sum is 33.

The square root of 1643431344 is about 40539.2568259459. The cubic root of 1643431344 is about 1180.0955931367.

The spelling of 1643431344 in words is "one billion, six hundred forty-three million, four hundred thirty-one thousand, three hundred forty-four".