643546 has 8 divisors (see below), whose sum is σ = 970164. Its totient is φ = 320160.

The previous prime is 643523. The next prime is 643547. The reversal of 643546 is 645346.

It can be written as a sum of positive squares in 2 ways, for example, as 622521 + 21025 = 789^2 + 145^2 .

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

It is a pancake number, because a pancake can be divided into 643546 parts by 1134 straight cuts.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (643547) by changing a digit.

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, 225 + ... + 1156.

2⁶⁴³⁵⁴⁶ is an apocalyptic number.

643546 is a deficient number, since it is larger than the sum of its proper divisors (326618).

643546 is a wasteful number, since it uses less digits than its factorization.

643546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1616.

The product of its digits is 8640, while the sum is 28.

The square root of 643546 is about 802.2131886226. The cubic root of 643546 is about 86.3362534190.

The spelling of 643546 in words is "six hundred forty-three thousand, five hundred forty-six".