1643779318764 has 24 divisors (see below), whose sum is σ = 4184165539008. Its totient is φ = 498114945040.

The previous prime is 1643779318739. The next prime is 1643779318793. The reversal of 1643779318764 is 4678139773461.

It is a Harshad number since it is a multiple of its sum of digits (66).

It is a junction number, because it is equal to n+sod(n) for n = 1643779318695 and 1643779318704.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6226436682 + ... + 6226436945.

It is an arithmetic number, because the mean of its divisors is an integer number (174340230792).

Almost surely, 2^{1643779318764} is an apocalyptic number.

It is an amenable number.

1643779318764 is an abundant number, since it is smaller than the sum of its proper divisors (2540386220244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1643779318764 is a wasteful number, since it uses less digits than its factorization.

1643779318764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12452873645 (or 12452873643 counting only the distinct ones).

The product of its digits is 128024064, while the sum is 66.

The spelling of 1643779318764 in words is "one trillion, six hundred forty-three billion, seven hundred seventy-nine million, three hundred eighteen thousand, seven hundred sixty-four".