639919059970381 has 2 divisors, whose sum is σ = 639919059970382. Its totient is φ = 639919059970380.

The previous prime is 639919059970369. The next prime is 639919059970403. The reversal of 639919059970381 is 183079950919936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 450809119494756 + 189109940475625 = 21232266^2 + 13751725^2 .

It is a cyclic number.

It is not a de Polignac number, because 639919059970381 - 2⁴⁵ = 604734687881549 is a prime.

It is a super-2 number, since 2×639919059970381² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639919059970181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319959529985190 + 319959529985191.

It is an arithmetic number, because the mean of its divisors is an integer number (319959529985191).

Almost surely, 2^{639919059970381} is an apocalyptic number.

It is an amenable number.

639919059970381 is a deficient number, since it is larger than the sum of its proper divisors (1).

639919059970381 is an equidigital number, since it uses as much as digits as its factorization.

639919059970381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 892820880, while the sum is 79.

The spelling of 639919059970381 in words is "six hundred thirty-nine trillion, nine hundred nineteen billion, fifty-nine million, nine hundred seventy thousand, three hundred eighty-one".