640828407834 has 24 divisors (see below), whose sum is σ = 1409184859680. Its totient is φ = 210421267848.

The previous prime is 640828407829. The next prime is 640828407851. The reversal of 640828407834 is 438704828046.

It is a happy number.

It is a super-2 number, since 2×640828407834² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 265682214 + ... + 265684625.

It is an arithmetic number, because the mean of its divisors is an integer number (58716035820).

Almost surely, 2^640828407834 is an apocalyptic number.

640828407834 is an abundant number, since it is smaller than the sum of its proper divisors (768356451846).

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

640828407834 is a wasteful number, since it uses less digits than its factorization.

640828407834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531366914 (or 531366911 counting only the distinct ones).

The product of its (nonzero) digits is 8257536, while the sum is 54.

The spelling of 640828407834 in words is "six hundred forty billion, eight hundred twenty-eight million, four hundred seven thousand, eight hundred thirty-four".