640522241 has 4 divisors (see below), whose sum is σ = 640917552. Its totient is φ = 640126932.

The previous prime is 640522237. The next prime is 640522247. The reversal of 640522241 is 142225046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 640522241 - 2² = 640522237 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 640522241.

It is not an unprimeable number, because it can be changed into a prime (640522247) 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, 195215 + ... + 198468.

It is an arithmetic number, because the mean of its divisors is an integer number (160229388).

Almost surely, 2^640522241 is an apocalyptic number.

It is an amenable number.

640522241 is a deficient number, since it is larger than the sum of its proper divisors (395311).

640522241 is a wasteful number, since it uses less digits than its factorization.

640522241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395310.

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 640522241 is about 25308.5408706231. The cubic root of 640522241 is about 862.0082152270.

Adding to 640522241 its reverse (142225046), we get a palindrome (782747287).

The spelling of 640522241 in words is "six hundred forty million, five hundred twenty-two thousand, two hundred forty-one".