1643245013 has 4 divisors (see below), whose sum is σ = 1645801248. Its totient is φ = 1640688780.

The previous prime is 1643244997. The next prime is 1643245033. The reversal of 1643245013 is 3105423461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1643245013 - 2⁴ = 1643244997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643245033) 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 3 ways as a sum of consecutive naturals, for example, 1277153 + ... + 1278438.

It is an arithmetic number, because the mean of its divisors is an integer number (411450312).

Almost surely, 2^1643245013 is an apocalyptic number.

It is an amenable number.

1643245013 is a deficient number, since it is larger than the sum of its proper divisors (2556235).

1643245013 is an equidigital number, since it uses as much as digits as its factorization.

1643245013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2556234.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 1643245013 is about 40536.9586056971. The cubic root of 1643245013 is about 1180.0509920031.

Adding to 1643245013 its reverse (3105423461), we get a palindrome (4748668474).

The spelling of 1643245013 in words is "one billion, six hundred forty-three million, two hundred forty-five thousand, thirteen".