640436064277 has 2 divisors, whose sum is σ = 640436064278. Its totient is φ = 640436064276.

The previous prime is 640436064223. The next prime is 640436064329. The reversal of 640436064277 is 772460634046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 532606580401 + 107829483876 = 729799^2 + 328374^2 .

It is a cyclic number.

It is not a de Polignac number, because 640436064277 - 2¹¹ = 640436062229 is a prime.

It is a super-2 number, since 2×640436064277² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 640436064277.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640436064677) 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, 320218032138 + 320218032139.

It is an arithmetic number, because the mean of its divisors is an integer number (320218032139).

Almost surely, 2^640436064277 is an apocalyptic number.

It is an amenable number.

640436064277 is a deficient number, since it is larger than the sum of its proper divisors (1).

640436064277 is an equidigital number, since it uses as much as digits as its factorization.

640436064277 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4064256, while the sum is 49.

The spelling of 640436064277 in words is "six hundred forty billion, four hundred thirty-six million, sixty-four thousand, two hundred seventy-seven".