1643321156 has 12 divisors (see below), whose sum is σ = 2883058668. Its totient is φ = 819590112.

The previous prime is 1643321143. The next prime is 1643321171. The reversal of 1643321156 is 6511233461.

It can be written as a sum of positive squares in 2 ways, for example, as 1326125056 + 317196100 = 36416^2 + 17810^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 515831 + ... + 519006.

It is an arithmetic number, because the mean of its divisors is an integer number (240254889).

Almost surely, 2^1643321156 is an apocalyptic number.

It is an amenable number.

1643321156 is a deficient number, since it is larger than the sum of its proper divisors (1239737512).

1643321156 is a wasteful number, since it uses less digits than its factorization.

1643321156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1035238 (or 1035236 counting only the distinct ones).

The product of its digits is 12960, while the sum is 32.

The square root of 1643321156 is about 40537.8977747983. The cubic root of 1643321156 is about 1180.0692183853.

The spelling of 1643321156 in words is "one billion, six hundred forty-three million, three hundred twenty-one thousand, one hundred fifty-six".