640546201 has 4 divisors (see below), whose sum is σ = 641124900. Its totient is φ = 639967504.

The previous prime is 640546199. The next prime is 640546219. The reversal of 640546201 is 102645046.

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 314707600 + 325838601 = 17740^2 + 18051^2 .

It is a cyclic number.

It is not a de Polignac number, because 640546201 - 2¹ = 640546199 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 640546201.

It is not an unprimeable number, because it can be changed into a prime (640546271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287686 + ... + 289903.

It is an arithmetic number, because the mean of its divisors is an integer number (160281225).

Almost surely, 2^640546201 is an apocalyptic number.

It is an amenable number.

640546201 is a deficient number, since it is larger than the sum of its proper divisors (578699).

640546201 is a wasteful number, since it uses less digits than its factorization.

640546201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578698.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 640546201 is about 25309.0142241850. The cubic root of 640546201 is about 862.0189634665.

The spelling of 640546201 in words is "six hundred forty million, five hundred forty-six thousand, two hundred one".