640601 has 4 divisors (see below), whose sum is σ = 689892. Its totient is φ = 591312.

The previous prime is 640589. The next prime is 640613. The reversal of 640601 is 106046.

640601 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.

It is an interprime number because it is at equal distance from previous prime (640589) and next prime (640613).

It can be written as a sum of positive squares in 2 ways, for example, as 274576 + 366025 = 524^2 + 605^2 .

It is a cyclic number.

It is not a de Polignac number, because 640601 - 2¹⁰ = 639577 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640601.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640601.

It is not an unprimeable number, because it can be changed into a prime (640621) 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, 24626 + ... + 24651.

It is an arithmetic number, because the mean of its divisors is an integer number (172473).

2⁶⁴⁰⁶⁰¹ is an apocalyptic number.

It is an amenable number.

640601 is a deficient number, since it is larger than the sum of its proper divisors (49291).

640601 is a wasteful number, since it uses less digits than its factorization.

640601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49290.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 640601 is about 800.3755368575. The cubic root of 640601 is about 86.2043544795.

Adding to 640601 its reverse (106046), we get a palindrome (746647).

The spelling of 640601 in words is "six hundred forty thousand, six hundred one".