645601 has 8 divisors (see below), whose sum is σ = 741600. Its totient is φ = 555840.

The previous prime is 645599. The next prime is 645611. The reversal of 645601 is 106546.

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 645601 - 2¹ = 645599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645611) 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 7 ways as a sum of consecutive naturals, for example, 1336 + ... + 1753.

It is an arithmetic number, because the mean of its divisors is an integer number (92700).

2⁶⁴⁵⁶⁰¹ is an apocalyptic number.

It is an amenable number.

645601 is a deficient number, since it is larger than the sum of its proper divisors (95999).

645601 is a wasteful number, since it uses less digits than its factorization.

645601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3119.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 645601 is about 803.4929993472. The cubic root of 645601 is about 86.4280533760.

It can be divided in two parts, 64 and 5601, that added together give a palindrome (5665).

The spelling of 645601 in words is "six hundred forty-five thousand, six hundred one".