639598081 has 2 divisors, whose sum is σ = 639598082. Its totient is φ = 639598080.

The previous prime is 639598067. The next prime is 639598093. The reversal of 639598081 is 180895936.

639598081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 622951681 + 16646400 = 24959^2 + 4080^2 .

It is a cyclic number.

It is not a de Polignac number, because 639598081 - 2¹³ = 639589889 is a prime.

It is a super-2 number, since 2×639598081² = 818171410437765122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (639598031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319799040 + 319799041.

It is an arithmetic number, because the mean of its divisors is an integer number (319799041).

Almost surely, 2^639598081 is an apocalyptic number.

It is an amenable number.

639598081 is a deficient number, since it is larger than the sum of its proper divisors (1).

639598081 is an equidigital number, since it uses as much as digits as its factorization.

639598081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 466560, while the sum is 49.

The square root of 639598081 is about 25290.2764120917. The cubic root of 639598081 is about 861.5934406872.

The spelling of 639598081 in words is "six hundred thirty-nine million, five hundred ninety-eight thousand, eighty-one".