1643248369 has 9 divisors (see below), whose sum is σ = 1911863961. Its totient is φ = 1408255380.

The previous prime is 1643248351. The next prime is 1643248391. The reversal of 1643248369 is 9638423461.

The square root of 1643248369 is 40537.

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

It is not a de Polignac number, because 1643248369 - 2⁷ = 1643248241 is a prime.

It is a super-2 number, since 2×1643248369² = 5400530404442320322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1643248309) 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 8 ways as a sum of consecutive naturals, for example, 280864 + ... + 286654.

It is an arithmetic number, because the mean of its divisors is an integer number (212429329).

Almost surely, 2^1643248369 is an apocalyptic number.

1643248369 is the 40537-th square number.

1643248369 is the 20269-th centered octagonal number.

It is an amenable number.

1643248369 is a deficient number, since it is larger than the sum of its proper divisors (268615592).

1643248369 is an frugal number, since it uses more digits than its factorization.

1643248369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11596 (or 5798 counting only the distinct ones).

The product of its digits is 746496, while the sum is 46.

The cubic root of 1643248369 is about 1180.0517953421.

The spelling of 1643248369 in words is "one billion, six hundred forty-three million, two hundred forty-eight thousand, three hundred sixty-nine".