640194166338 has 32 divisors (see below), whose sum is σ = 1308907192320. Its totient is φ = 208682786640.

The previous prime is 640194166331. The next prime is 640194166349. The reversal of 640194166338 is 833661491046.

It is a super-2 number, since 2×640194166338² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640194166331) 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 15 ways as a sum of consecutive naturals, for example, 4666570 + ... + 4801797.

It is an arithmetic number, because the mean of its divisors is an integer number (40903349760).

Almost surely, 2^640194166338 is an apocalyptic number.

640194166338 is an abundant number, since it is smaller than the sum of its proper divisors (668713025982).

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

640194166338 is a wasteful number, since it uses less digits than its factorization.

640194166338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9468622.

The product of its (nonzero) digits is 2239488, while the sum is 51.

The spelling of 640194166338 in words is "six hundred forty billion, one hundred ninety-four million, one hundred sixty-six thousand, three hundred thirty-eight".