1643140444 has 48 divisors (see below), whose sum is σ = 3320553600. Its totient is φ = 703598400.

The previous prime is 1643140441. The next prime is 1643140451. The reversal of 1643140444 is 4440413461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643140441) 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, 145887 + ... + 156745.

It is an arithmetic number, because the mean of its divisors is an integer number (69178200).

Almost surely, 2^1643140444 is an apocalyptic number.

It is an amenable number.

1643140444 is an abundant number, since it is smaller than the sum of its proper divisors (1677413156).

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

1643140444 is a wasteful number, since it uses less digits than its factorization.

1643140444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11074 (or 11072 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 31.

The square root of 1643140444 is about 40535.6687868845. The cubic root of 1643140444 is about 1180.0259603596.

The spelling of 1643140444 in words is "one billion, six hundred forty-three million, one hundred forty thousand, four hundred forty-four".