640552225321 has 2 divisors, whose sum is σ = 640552225322. Its totient is φ = 640552225320.

The previous prime is 640552225277. The next prime is 640552225331. The reversal of 640552225321 is 123522255046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 374745987225 + 265806238096 = 612165^2 + 515564^2 .

It is a cyclic number.

It is not a de Polignac number, because 640552225321 - 2⁷ = 640552225193 is a prime.

It is not a weakly prime, because it can be changed into another prime (640552225331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320276112660 + 320276112661.

It is an arithmetic number, because the mean of its divisors is an integer number (320276112661).

Almost surely, 2^640552225321 is an apocalyptic number.

It is an amenable number.

640552225321 is a deficient number, since it is larger than the sum of its proper divisors (1).

640552225321 is an equidigital number, since it uses as much as digits as its factorization.

640552225321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144000, while the sum is 37.

The spelling of 640552225321 in words is "six hundred forty billion, five hundred fifty-two million, two hundred twenty-five thousand, three hundred twenty-one".