638927099851 has 2 divisors, whose sum is σ = 638927099852. Its totient is φ = 638927099850.

The previous prime is 638927099819. The next prime is 638927099873. The reversal of 638927099851 is 158990729836.

638927099851 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 is a cyclic number.

It is not a de Polignac number, because 638927099851 - 2⁵ = 638927099819 is a prime.

It is not a weakly prime, because it can be changed into another prime (638927099351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319463549925 + 319463549926.

It is an arithmetic number, because the mean of its divisors is an integer number (319463549926).

Almost surely, 2^638927099851 is an apocalyptic number.

638927099851 is a deficient number, since it is larger than the sum of its proper divisors (1).

638927099851 is an equidigital number, since it uses as much as digits as its factorization.

638927099851 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58786560, while the sum is 67.

The spelling of 638927099851 in words is "six hundred thirty-eight billion, nine hundred twenty-seven million, ninety-nine thousand, eight hundred fifty-one".