1643079220 has 12 divisors (see below), whose sum is σ = 3450466404. Its totient is φ = 657231680.

The previous prime is 1643079203. The next prime is 1643079227. The reversal of 1643079220 is 229703461.

It can be written as a sum of positive squares in 2 ways, for example, as 610485264 + 1032593956 = 24708^2 + 32134^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643079227) 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, 41076961 + ... + 41077000.

It is an arithmetic number, because the mean of its divisors is an integer number (287538867).

Almost surely, 2^1643079220 is an apocalyptic number.

1643079220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1643079220 is an abundant number, since it is smaller than the sum of its proper divisors (1807387184).

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

1643079220 is a wasteful number, since it uses less digits than its factorization.

1643079220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82153970 (or 82153968 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 1643079220 is about 40534.9135930990. The cubic root of 1643079220 is about 1180.0113041146.

The spelling of 1643079220 in words is "one billion, six hundred forty-three million, seventy-nine thousand, two hundred twenty".