640142400066 has 64 divisors (see below), whose sum is σ = 1483804780416. Its totient is φ = 182341555200.

The previous prime is 640142400059. The next prime is 640142400091. The reversal of 640142400066 is 660004241046.

It is a Curzon number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 3876180 + ... + 4037951.

It is an arithmetic number, because the mean of its divisors is an integer number (23184449694).

Almost surely, 2^640142400066 is an apocalyptic number.

640142400066 is an abundant number, since it is smaller than the sum of its proper divisors (843662380350).

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

640142400066 is a wasteful number, since it uses less digits than its factorization.

640142400066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7914227.

The product of its (nonzero) digits is 27648, while the sum is 33.

The spelling of 640142400066 in words is "six hundred forty billion, one hundred forty-two million, four hundred thousand, sixty-six".