1643543958 has 48 divisors (see below), whose sum is σ = 3850698240. Its totient is φ = 458111040.

The previous prime is 1643543953. The next prime is 1643543971. The reversal of 1643543958 is 8593453461.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643543953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 58963 + ... + 82241.

It is an arithmetic number, because the mean of its divisors is an integer number (80222880).

Almost surely, 2^1643543958 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1643543958, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1925349120).

1643543958 is an abundant number, since it is smaller than the sum of its proper divisors (2207154282).

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

1643543958 is a wasteful number, since it uses less digits than its factorization.

1643543958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23373 (or 23332 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 48.

The square root of 1643543958 is about 40540.6457521337. The cubic root of 1643543958 is about 1180.1225473607.

The spelling of 1643543958 in words is "one billion, six hundred forty-three million, five hundred forty-three thousand, nine hundred fifty-eight".