643355 has 8 divisors (see below), whose sum is σ = 776832. Its totient is φ = 511488.

The previous prime is 643303. The next prime is 643369. The reversal of 643355 is 553346.

643355 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 cyclic number.

It is not a de Polignac number, because 643355 - 2⁸ = 643099 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 827 + ... + 1403.

It is an arithmetic number, because the mean of its divisors is an integer number (97104).

2⁶⁴³³⁵⁵ is an apocalyptic number.

643355 is a deficient number, since it is larger than the sum of its proper divisors (133477).

643355 is a wasteful number, since it uses less digits than its factorization.

643355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805.

The product of its digits is 5400, while the sum is 26.

The square root of 643355 is about 802.0941341264. The cubic root of 643355 is about 86.3277112396.

Subtracting from 643355 its reverse (553346), we obtain a palindrome (90009).

The spelling of 643355 in words is "six hundred forty-three thousand, three hundred fifty-five".