639520596641 has 2 divisors, whose sum is σ = 639520596642. Its totient is φ = 639520596640.

The previous prime is 639520596619. The next prime is 639520596661. The reversal of 639520596641 is 146695025936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 621462612241 + 18057984400 = 788329^2 + 134380^2 .

It is a cyclic number.

It is not a de Polignac number, because 639520596641 - 2¹⁰ = 639520595617 is a prime.

It is not a weakly prime, because it can be changed into another prime (639520596661) 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, 319760298320 + 319760298321.

It is an arithmetic number, because the mean of its divisors is an integer number (319760298321).

Almost surely, 2^639520596641 is an apocalyptic number.

It is an amenable number.

639520596641 is a deficient number, since it is larger than the sum of its proper divisors (1).

639520596641 is an equidigital number, since it uses as much as digits as its factorization.

639520596641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10497600, while the sum is 56.

The spelling of 639520596641 in words is "six hundred thirty-nine billion, five hundred twenty million, five hundred ninety-six thousand, six hundred forty-one".