640361 has 4 divisors (see below), whose sum is σ = 642372. Its totient is φ = 638352.

The previous prime is 640333. The next prime is 640363. The reversal of 640361 is 163046.

640361 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 can be written as a sum of positive squares in 2 ways, for example, as 414736 + 225625 = 644^2 + 475^2 .

It is a cyclic number.

It is not a de Polignac number, because 640361 - 2¹⁰ = 639337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640363) 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, 410 + ... + 1203.

It is an arithmetic number, because the mean of its divisors is an integer number (160593).

2⁶⁴⁰³⁶¹ is an apocalyptic number.

It is an amenable number.

640361 is a deficient number, since it is larger than the sum of its proper divisors (2011).

640361 is a wasteful number, since it uses less digits than its factorization.

640361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2010.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 640361 is about 800.2255931923. The cubic root of 640361 is about 86.1935876999.

It can be divided in two parts, 640 and 361, that added together give a palindrome (1001).

The spelling of 640361 in words is "six hundred forty thousand, three hundred sixty-one".