640045601 has 4 divisors (see below), whose sum is σ = 689279892. Its totient is φ = 590811312.

The previous prime is 640045589. The next prime is 640045643. The reversal of 640045601 is 106540046.

It is a happy number.

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 345030625 + 295014976 = 18575^2 + 17176^2 .

It is not a de Polignac number, because 640045601 - 2⁶ = 640045537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640045661) 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, 24617126 + ... + 24617151.

It is an arithmetic number, because the mean of its divisors is an integer number (172319973).

Almost surely, 2^640045601 is an apocalyptic number.

It is an amenable number.

640045601 is a deficient number, since it is larger than the sum of its proper divisors (49234291).

640045601 is a wasteful number, since it uses less digits than its factorization.

640045601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49234290.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 640045601 is about 25299.1225341908. The cubic root of 640045601 is about 861.7943431051.

Adding to 640045601 its reverse (106540046), we get a palindrome (746585647).

The spelling of 640045601 in words is "six hundred forty million, forty-five thousand, six hundred one".