643900272 has 80 divisors (see below), whose sum is σ = 1827144960. Its totient is φ = 194489856.

The previous prime is 643900267. The next prime is 643900273. The reversal of 643900272 is 272009346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643900273) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5628 + ... + 36324.

It is an arithmetic number, because the mean of its divisors is an integer number (22839312).

Almost surely, 2^643900272 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 643900272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (913572480).

643900272 is an abundant number, since it is smaller than the sum of its proper divisors (1183244688).

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

643900272 is a wasteful number, since it uses less digits than its factorization.

643900272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30750 (or 30744 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 33.

The square root of 643900272 is about 25375.1900879580. The cubic root of 643900272 is about 863.5209321194.

The spelling of 643900272 in words is "six hundred forty-three million, nine hundred thousand, two hundred seventy-two".