640403946100 has 18 divisors (see below), whose sum is σ = 1389676563254. Its totient is φ = 256161578400.

The previous prime is 640403946059. The next prime is 640403946101. The reversal of 640403946100 is 1649304046.

It can be written as a sum of positive squares in 3 ways, for example, as 234334864 + 640169611236 = 15308^2 + 800106^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 640403946100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640403946101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3202019631 + ... + 3202019830.

Almost surely, 2^640403946100 is an apocalyptic number.

It is an amenable number.

640403946100 is an abundant number, since it is smaller than the sum of its proper divisors (749272617154).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640403946100 is a wasteful number, since it uses less digits than its factorization.

640403946100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6404039475 (or 6404039468 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 37.

It can be divided in two parts, 640403946 and 100, that added together give a palindrome (640404046).

The spelling of 640403946100 in words is "six hundred forty billion, four hundred three million, nine hundred forty-six thousand, one hundred".