643378 has 8 divisors (see below), whose sum is σ = 1015920. Its totient is φ = 304740.

The previous prime is 643373. The next prime is 643403. The reversal of 643378 is 873346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (643373) 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, 8428 + ... + 8503.

It is an arithmetic number, because the mean of its divisors is an integer number (126990).

2⁶⁴³³⁷⁸ is an apocalyptic number.

643378 is a deficient number, since it is larger than the sum of its proper divisors (372542).

643378 is a wasteful number, since it uses less digits than its factorization.

643378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16952.

The product of its digits is 12096, while the sum is 31.

The square root of 643378 is about 802.1084714675. The cubic root of 643378 is about 86.3287399685.

The spelling of 643378 in words is "six hundred forty-three thousand, three hundred seventy-eight".