643948 has 24 divisors (see below), whose sum is σ = 1223600. Its totient is φ = 295488.

The previous prime is 643927. The next prime is 643949. The reversal of 643948 is 849346.

It is a d-powerful number, because it can be written as 6⁶ + 4³ + 9⁶ + 3⁵ + 4⁸ + 8 .

It is not an unprimeable number, because it can be changed into a prime (643949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2698 + ... + 2926.

2⁶⁴³⁹⁴⁸ is an apocalyptic number.

It is an amenable number.

643948 is a deficient number, since it is larger than the sum of its proper divisors (579652).

643948 is a wasteful number, since it uses less digits than its factorization.

643948 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289 (or 287 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 643948 is about 802.4637063444. The cubic root of 643948 is about 86.3542267260.

The spelling of 643948 in words is "six hundred forty-three thousand, nine hundred forty-eight".