1643329444 has 9 divisors (see below), whose sum is σ = 2875968417. Its totient is φ = 821624184.

The previous prime is 1643329439. The next prime is 1643329459. The reversal of 1643329444 is 4449233461.

The square root of 1643329444 is 40538.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1270067044 + 373262400 = 35638^2 + 19320^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1643329397 and 1643329406.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 70942 + ... + 91210.

Almost surely, 2^1643329444 is an apocalyptic number.

1643329444 is the 40538-th square number.

It is an amenable number.

1643329444 is a deficient number, since it is larger than the sum of its proper divisors (1232638973).

1643329444 is an frugal number, since it uses more digits than its factorization.

1643329444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40542 (or 20271 counting only the distinct ones).

The product of its digits is 248832, while the sum is 40.

The cubic root of 1643329444 is about 1180.0712022533.

The spelling of 1643329444 in words is "one billion, six hundred forty-three million, three hundred twenty-nine thousand, four hundred forty-four".