643534 has 8 divisors (see below), whose sum is σ = 977760. Its totient is φ = 317616.

The previous prime is 643523. The next prime is 643547. The reversal of 643534 is 435346.

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

It is a junction number, because it is equal to n+sod(n) for n = 643499 and 643508.

It is a congruent number.

It is an unprimeable number.

643534 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1879 + ... + 2194.

It is an arithmetic number, because the mean of its divisors is an integer number (122220).

2⁶⁴³⁵³⁴ is an apocalyptic number.

643534 is a deficient number, since it is larger than the sum of its proper divisors (334226).

643534 is a wasteful number, since it uses less digits than its factorization.

643534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4154.

The product of its digits is 4320, while the sum is 25.

The square root of 643534 is about 802.2057092791. The cubic root of 643534 is about 86.3357167873.

The spelling of 643534 in words is "six hundred forty-three thousand, five hundred thirty-four".