1643204541 has 16 divisors (see below), whose sum is σ = 2414760768. Its totient is φ = 985612800.

The previous prime is 1643204533. The next prime is 1643204551. The reversal of 1643204541 is 1454023461.

It is not a de Polignac number, because 1643204541 - 2³ = 1643204533 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1643204499 and 1643204508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643204551) 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 15 ways as a sum of consecutive naturals, for example, 253470 + ... + 259871.

It is an arithmetic number, because the mean of its divisors is an integer number (150922548).

Almost surely, 2^1643204541 is an apocalyptic number.

1643204541 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1643204541 is a deficient number, since it is larger than the sum of its proper divisors (771556227).

1643204541 is a wasteful number, since it uses less digits than its factorization.

1643204541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513452.

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 1643204541 is about 40536.4594038503. The cubic root of 1643204541 is about 1180.0413039741.

It can be divided in two parts, 164320 and 4541, that added together give a palindrome (168861).

The spelling of 1643204541 in words is "one billion, six hundred forty-three million, two hundred four thousand, five hundred forty-one".