1643045403 has 4 divisors (see below), whose sum is σ = 2190727208. Its totient is φ = 1095363600.

The previous prime is 1643045377. The next prime is 1643045447. The reversal of 1643045403 is 3045403461.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1643045403 - 2¹⁰ = 1643044379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643045483) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 273840898 + ... + 273840903.

It is an arithmetic number, because the mean of its divisors is an integer number (547681802).

Almost surely, 2^1643045403 is an apocalyptic number.

1643045403 is a deficient number, since it is larger than the sum of its proper divisors (547681805).

1643045403 is an equidigital number, since it uses as much as digits as its factorization.

1643045403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547681804.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 1643045403 is about 40534.4964567219. The cubic root of 1643045403 is about 1180.0032085999.

Adding to 1643045403 its reverse (3045403461), we get a palindrome (4688448864).

The spelling of 1643045403 in words is "one billion, six hundred forty-three million, forty-five thousand, four hundred three".