640611384418 has 4 divisors (see below), whose sum is σ = 960917076630. Its totient is φ = 320305692208.

The previous prime is 640611384397. The next prime is 640611384451. The reversal of 640611384418 is 814483116046.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 560840725449 + 79770658969 = 748893^2 + 282437^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160152846103 + ... + 160152846106.

Almost surely, 2^640611384418 is an apocalyptic number.

640611384418 is a deficient number, since it is larger than the sum of its proper divisors (320305692212).

640611384418 is a wasteful number, since it uses less digits than its factorization.

640611384418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320305692211.

The product of its (nonzero) digits is 442368, while the sum is 46.

The spelling of 640611384418 in words is "six hundred forty billion, six hundred eleven million, three hundred eighty-four thousand, four hundred eighteen".