639625003837 has 2 divisors, whose sum is σ = 639625003838. Its totient is φ = 639625003836.

The previous prime is 639625003813. The next prime is 639625003867. The reversal of 639625003837 is 738300526936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 631398695236 + 8226308601 = 794606^2 + 90699^2 .

It is a cyclic number.

It is not a de Polignac number, because 639625003837 - 2⁷ = 639625003709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639625003867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319812501918 + 319812501919.

It is an arithmetic number, because the mean of its divisors is an integer number (319812501919).

Almost surely, 2^639625003837 is an apocalyptic number.

It is an amenable number.

639625003837 is a deficient number, since it is larger than the sum of its proper divisors (1).

639625003837 is an equidigital number, since it uses as much as digits as its factorization.

639625003837 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4898880, while the sum is 52.

The spelling of 639625003837 in words is "six hundred thirty-nine billion, six hundred twenty-five million, three thousand, eight hundred thirty-seven".