1643663419 has 18 divisors (see below), whose sum is σ = 1768382180. Its totient is φ = 1523503800.

The previous prime is 1643663407. The next prime is 1643663453. The reversal of 1643663419 is 9143663461.

It is not a de Polignac number, because 1643663419 - 2⁵ = 1643663387 is a prime.

It is a super-2 number, since 2×1643663419² = 5403258869917539122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643663459) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 12546984 + ... + 12547114.

Almost surely, 2^1643663419 is an apocalyptic number.

1643663419 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1643663419 is a deficient number, since it is larger than the sum of its proper divisors (124718761).

1643663419 is an frugal number, since it uses more digits than its factorization.

1643663419 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423 (or 221 counting only the distinct ones).

The product of its digits is 279936, while the sum is 43.

The square root of 1643663419 is about 40542.1190738718. The cubic root of 1643663419 is about 1180.1511390722.

The spelling of 1643663419 in words is "one billion, six hundred forty-three million, six hundred sixty-three thousand, four hundred nineteen".