643265 has 8 divisors (see below), whose sum is σ = 882240. Its totient is φ = 441072.

The previous prime is 643243. The next prime is 643273. The reversal of 643265 is 562346.

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 643265 - 2⁸ = 643009 is a prime.

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, 9155 + ... + 9224.

It is an arithmetic number, because the mean of its divisors is an integer number (110280).

2⁶⁴³²⁶⁵ is an apocalyptic number.

It is an amenable number.

643265 is a deficient number, since it is larger than the sum of its proper divisors (238975).

643265 is a wasteful number, since it uses less digits than its factorization.

643265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18391.

The product of its digits is 4320, while the sum is 26.

The square root of 643265 is about 802.0380290236. The cubic root of 643265 is about 86.3236855429.

The spelling of 643265 in words is "six hundred forty-three thousand, two hundred sixty-five".