640558802826 has 48 divisors (see below), whose sum is σ = 1469694684744. Its totient is φ = 200935360512.

The previous prime is 640558802801. The next prime is 640558802839. The reversal of 640558802826 is 628208855046.

It is a happy number.

640558802826 is a `hidden beast` number, since 6 + 4 + 0 + 558 + 8 + 0 + 2 + 82 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 422306322201 + 218252480625 = 649851^2 + 467175^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2501250 + ... + 2745426.

Almost surely, 2^640558802826 is an apocalyptic number.

640558802826 is an abundant number, since it is smaller than the sum of its proper divisors (829135881918).

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

640558802826 is a wasteful number, since it uses less digits than its factorization.

640558802826 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252775 (or 252772 counting only the distinct ones).

The product of its (nonzero) digits is 7372800, while the sum is 54.

The spelling of 640558802826 in words is "six hundred forty billion, five hundred fifty-eight million, eight hundred two thousand, eight hundred twenty-six".