638403576929 has 2 divisors, whose sum is σ = 638403576930. Its totient is φ = 638403576928.

The previous prime is 638403576817. The next prime is 638403576947. The reversal of 638403576929 is 929675304836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 600899381329 + 37504195600 = 775177^2 + 193660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638403576929 is a prime.

It is not a weakly prime, because it can be changed into another prime (638403576989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319201788464 + 319201788465.

It is an arithmetic number, because the mean of its divisors is an integer number (319201788465).

Almost surely, 2^638403576929 is an apocalyptic number.

It is an amenable number.

638403576929 is a deficient number, since it is larger than the sum of its proper divisors (1).

638403576929 is an equidigital number, since it uses as much as digits as its factorization.

638403576929 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 62.

The spelling of 638403576929 in words is "six hundred thirty-eight billion, four hundred three million, five hundred seventy-six thousand, nine hundred twenty-nine".