640636896830 has 16 divisors (see below), whose sum is σ = 1317881616480. Its totient is φ = 219646936032.

The previous prime is 640636896817. The next prime is 640636896841. The reversal of 640636896830 is 38698636046.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 640636896830.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4575977765 + ... + 4575977904.

It is an arithmetic number, because the mean of its divisors is an integer number (82367601030).

Almost surely, 2^640636896830 is an apocalyptic number.

640636896830 is an abundant number, since it is smaller than the sum of its proper divisors (677244719650).

640636896830 is a wasteful number, since it uses less digits than its factorization.

640636896830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9151955683.

The product of its (nonzero) digits is 26873856, while the sum is 59.

The spelling of 640636896830 in words is "six hundred forty billion, six hundred thirty-six million, eight hundred ninety-six thousand, eight hundred thirty".