640820611326 has 64 divisors (see below), whose sum is σ = 1557329241600. Its totient is φ = 171606435840.

The previous prime is 640820611283. The next prime is 640820611339. The reversal of 640820611326 is 623116028046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1689976 + ... + 2034123.

It is an arithmetic number, because the mean of its divisors is an integer number (24333269400).

Almost surely, 2^640820611326 is an apocalyptic number.

640820611326 is an abundant number, since it is smaller than the sum of its proper divisors (916508630274).

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

640820611326 is a wasteful number, since it uses less digits than its factorization.

640820611326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3724369.

The product of its (nonzero) digits is 82944, while the sum is 39.

The spelling of 640820611326 in words is "six hundred forty billion, eight hundred twenty million, six hundred eleven thousand, three hundred twenty-six".