1643221452 has 24 divisors (see below), whose sum is σ = 3927701232. Its totient is φ = 534380800.

The previous prime is 1643221357. The next prime is 1643221457. The reversal of 1643221452 is 2541223461.

It is not an unprimeable number, because it can be changed into a prime (1643221457) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1669449 + ... + 1670432.

It is an arithmetic number, because the mean of its divisors is an integer number (163654218).

Almost surely, 2^1643221452 is an apocalyptic number.

1643221452 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1643221452 is an abundant number, since it is smaller than the sum of its proper divisors (2284479780).

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

1643221452 is a wasteful number, since it uses less digits than its factorization.

1643221452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3339929 (or 3339927 counting only the distinct ones).

The product of its digits is 11520, while the sum is 30.

The square root of 1643221452 is about 40536.6679933119. The cubic root of 1643221452 is about 1180.0453520824.

The spelling of 1643221452 in words is "one billion, six hundred forty-three million, two hundred twenty-one thousand, four hundred fifty-two".