643127320 has 128 divisors (see below), whose sum is σ = 1631093760. Its totient is φ = 226216960.

The previous prime is 643127269. The next prime is 643127341. The reversal of 643127320 is 23721346.

It is a super-2 number, since 2×643127320² = 827225499460764800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2833047 + ... + 2833273.

It is an arithmetic number, because the mean of its divisors is an integer number (12742920).

Almost surely, 2^643127320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643127320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (815546880).

643127320 is an abundant number, since it is smaller than the sum of its proper divisors (987966440).

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

643127320 is a wasteful number, since it uses less digits than its factorization.

643127320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 429 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 28.

The square root of 643127320 is about 25359.9550472788. The cubic root of 643127320 is about 863.1752639486.

Adding to 643127320 its reverse (23721346), we get a palindrome (666848666).

The spelling of 643127320 in words is "six hundred forty-three million, one hundred twenty-seven thousand, three hundred twenty".