638026778029 has 2 divisors, whose sum is σ = 638026778030. Its totient is φ = 638026778028.

The previous prime is 638026777981. The next prime is 638026778047. The reversal of 638026778029 is 920877620836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 619365852004 + 18660926025 = 786998^2 + 136605^2 .

It is a cyclic number.

It is not a de Polignac number, because 638026778029 - 2²⁷ = 637892560301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638026778329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319013389014 + 319013389015.

It is an arithmetic number, because the mean of its divisors is an integer number (319013389015).

Almost surely, 2^638026778029 is an apocalyptic number.

It is an amenable number.

638026778029 is a deficient number, since it is larger than the sum of its proper divisors (1).

638026778029 is an equidigital number, since it uses as much as digits as its factorization.

638026778029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12192768, while the sum is 58.

The spelling of 638026778029 in words is "six hundred thirty-eight billion, twenty-six million, seven hundred seventy-eight thousand, twenty-nine".