643948272 has 80 divisors (see below), whose sum is σ = 2016418560. Its totient is φ = 195134400.

The previous prime is 643948267. The next prime is 643948297. The reversal of 643948272 is 272849346.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63004 + ... + 72507.

It is an arithmetic number, because the mean of its divisors is an integer number (25205232).

Almost surely, 2^643948272 is an apocalyptic number.

It is an amenable number.

643948272 is an abundant number, since it is smaller than the sum of its proper divisors (1372470288).

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

643948272 is a wasteful number, since it uses less digits than its factorization.

643948272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135539 (or 135527 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 643948272 is about 25376.1358760549. The cubic root of 643948272 is about 863.5423888453.

The spelling of 643948272 in words is "six hundred forty-three million, nine hundred forty-eight thousand, two hundred seventy-two".