646843513129 has 4 divisors (see below), whose sum is σ = 705647468880. Its totient is φ = 588039557380.

The previous prime is 646843513117. The next prime is 646843513153. The reversal of 646843513129 is 921315348646.

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 de Polignac number, because none of the positive numbers 2^k-646843513129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646843510129) 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, 29401977859 + ... + 29401977880.

It is an arithmetic number, because the mean of its divisors is an integer number (176411867220).

Almost surely, 2^646843513129 is an apocalyptic number.

It is an amenable number.

646843513129 is a deficient number, since it is larger than the sum of its proper divisors (58803955751).

646843513129 is a wasteful number, since it uses less digits than its factorization.

646843513129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58803955750.

The product of its digits is 3732480, while the sum is 52.

The spelling of 646843513129 in words is "six hundred forty-six billion, eight hundred forty-three million, five hundred thirteen thousand, one hundred twenty-nine".