639953201 has 2 divisors, whose sum is σ = 639953202. Its totient is φ = 639953200.

The previous prime is 639953191. The next prime is 639953203. The reversal of 639953201 is 102359936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 551122576 + 88830625 = 23476^2 + 9425^2 .

It is a cyclic number.

It is not a de Polignac number, because 639953201 - 2¹⁰ = 639952177 is a prime.

Together with 639953203, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (639953203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319976600 + 319976601.

It is an arithmetic number, because the mean of its divisors is an integer number (319976601).

Almost surely, 2^639953201 is an apocalyptic number.

It is an amenable number.

639953201 is a deficient number, since it is larger than the sum of its proper divisors (1).

639953201 is an equidigital number, since it uses as much as digits as its factorization.

639953201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43740, while the sum is 38.

The square root of 639953201 is about 25297.2963179862. The cubic root of 639953201 is about 861.7528702114.

The spelling of 639953201 in words is "six hundred thirty-nine million, nine hundred fifty-three thousand, two hundred one".