643379 has 8 divisors (see below), whose sum is σ = 732672. Its totient is φ = 559240.

The previous prime is 643373. The next prime is 643403. The reversal of 643379 is 973346.

643379 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a de Polignac number, because none of the positive numbers 2^k-643379 is a prime.

It is an Ulam number.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 1019 + ... + 1524.

It is an arithmetic number, because the mean of its divisors is an integer number (91584).

2⁶⁴³³⁷⁹ is an apocalyptic number.

643379 is a deficient number, since it is larger than the sum of its proper divisors (89293).

643379 is a wasteful number, since it uses less digits than its factorization.

643379 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2577.

The product of its digits is 13608, while the sum is 32.

The square root of 643379 is about 802.1090948244. The cubic root of 643379 is about 86.3287846953.

It can be divided in two parts, 64337 and 9, that added together give a palindrome (64346).

The spelling of 643379 in words is "six hundred forty-three thousand, three hundred seventy-nine".