643607 has 4 divisors (see below), whose sum is σ = 645216. Its totient is φ = 642000.

The previous prime is 643589. The next prime is 643619. The reversal of 643607 is 706346.

643607 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 706346 = 2 ⋅353173.

It is a cyclic number.

It is not a de Polignac number, because 643607 - 2¹² = 639511 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643697) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323 + ... + 1179.

It is an arithmetic number, because the mean of its divisors is an integer number (161304).

2⁶⁴³⁶⁰⁷ is an apocalyptic number.

643607 is a deficient number, since it is larger than the sum of its proper divisors (1609).

643607 is an equidigital number, since it uses as much as digits as its factorization.

643607 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1608.

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 643607 is about 802.2512075404. The cubic root of 643607 is about 86.3389811934.

The spelling of 643607 in words is "six hundred forty-three thousand, six hundred seven".