643446 has 12 divisors (see below), whose sum is σ = 1394172. Its totient is φ = 214476.

The previous prime is 643439. The next prime is 643453. The reversal of 643446 is 644346.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (643439) and next prime (643453).

It is a congruent number.

It is an unprimeable number.

643446 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 5 ways as a sum of consecutive naturals, for example, 17856 + ... + 17891.

It is an arithmetic number, because the mean of its divisors is an integer number (116181).

2⁶⁴³⁴⁴⁶ is an apocalyptic number.

643446 is an abundant number, since it is smaller than the sum of its proper divisors (750726).

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

643446 is a wasteful number, since it uses less digits than its factorization.

643446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35755 (or 35752 counting only the distinct ones).

The product of its digits is 6912, while the sum is 27.

The square root of 643446 is about 802.1508586295. The cubic root of 643446 is about 86.3317812846.

Subtracting 643446 from its reverse (644346), we obtain a square (900 = 30²).

It can be divided in two parts, 643 and 446, that added together give a square (1089 = 33²).

The spelling of 643446 in words is "six hundred forty-three thousand, four hundred forty-six".