643219 has 4 divisors (see below), whose sum is σ = 664000. Its totient is φ = 622440.

The previous prime is 643217. The next prime is 643231. The reversal of 643219 is 912346.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 643219 - 2¹ = 643217 is a prime.

It is a super-2 number, since 2×643219² = 827461363922, which contains 22 as substring.

It is a Duffinian number.

643219 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 643193 and 643202.

It is not an unprimeable number, because it can be changed into a prime (643213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10344 + ... + 10405.

It is an arithmetic number, because the mean of its divisors is an integer number (166000).

2⁶⁴³²¹⁹ is an apocalyptic number.

643219 is a deficient number, since it is larger than the sum of its proper divisors (20781).

643219 is a wasteful number, since it uses less digits than its factorization.

643219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20780.

The product of its digits is 1296, while the sum is 25.

The square root of 643219 is about 802.0093515664. The cubic root of 643219 is about 86.3216278195.

The spelling of 643219 in words is "six hundred forty-three thousand, two hundred nineteen".