640223776767 has 4 divisors (see below), whose sum is σ = 853631702360. Its totient is φ = 426815851176.

The previous prime is 640223776733. The next prime is 640223776817. The reversal of 640223776767 is 767677322046.

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

It is not a de Polignac number, because 640223776767 - 2⁷ = 640223776639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640223776067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106703962792 + ... + 106703962797.

It is an arithmetic number, because the mean of its divisors is an integer number (213407925590).

Almost surely, 2^640223776767 is an apocalyptic number.

640223776767 is a deficient number, since it is larger than the sum of its proper divisors (213407925593).

640223776767 is a wasteful number, since it uses less digits than its factorization.

640223776767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213407925592.

The product of its (nonzero) digits is 24893568, while the sum is 57.

The spelling of 640223776767 in words is "six hundred forty billion, two hundred twenty-three million, seven hundred seventy-six thousand, seven hundred sixty-seven".