640667528164 has 6 divisors (see below), whose sum is σ = 1121168174294. Its totient is φ = 320333764080.

The previous prime is 640667528161. The next prime is 640667528177. The reversal of 640667528164 is 461825766046.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 616630126564 + 24037401600 = 785258^2 + 155040^2 .

It is a super-3 number, since 3×640667528164³ (a number of 36 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (640667528161) 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 as a sum of consecutive naturals, namely, 80083441017 + ... + 80083441024.

Almost surely, 2^640667528164 is an apocalyptic number.

It is an amenable number.

640667528164 is a deficient number, since it is larger than the sum of its proper divisors (480500646130).

640667528164 is a wasteful number, since it uses less digits than its factorization.

640667528164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160166882045 (or 160166882043 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 55.

The spelling of 640667528164 in words is "six hundred forty billion, six hundred sixty-seven million, five hundred twenty-eight thousand, one hundred sixty-four".