640436368210 has 16 divisors (see below), whose sum is σ = 1152801037656. Its totient is φ = 256171086208.

The previous prime is 640436368207. The next prime is 640436368211. The reversal of 640436368210 is 12863634046.

It can be written as a sum of positive squares in 4 ways, for example, as 585740723569 + 54695644641 = 765337^2 + 233871^2 .

It is not an unprimeable number, because it can be changed into a prime (640436368211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 425604 + ... + 1209136.

Almost surely, 2^640436368210 is an apocalyptic number.

640436368210 is a deficient number, since it is larger than the sum of its proper divisors (512364669446).

640436368210 is a wasteful number, since it uses less digits than its factorization.

640436368210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 865277.

The product of its (nonzero) digits is 497664, while the sum is 43.

The spelling of 640436368210 in words is "six hundred forty billion, four hundred thirty-six million, three hundred sixty-eight thousand, two hundred ten".