638047761979 has 2 divisors, whose sum is σ = 638047761980. Its totient is φ = 638047761978.

The previous prime is 638047761931. The next prime is 638047762057. The reversal of 638047761979 is 979167740836.

638047761979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638047761979 - 2¹⁷ = 638047630907 is a prime.

It is not a weakly prime, because it can be changed into another prime (638047761919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319023880989 + 319023880990.

It is an arithmetic number, because the mean of its divisors is an integer number (319023880990).

Almost surely, 2^638047761979 is an apocalyptic number.

638047761979 is a deficient number, since it is larger than the sum of its proper divisors (1).

638047761979 is an equidigital number, since it uses as much as digits as its factorization.

638047761979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96018048, while the sum is 67.

The spelling of 638047761979 in words is "six hundred thirty-eight billion, forty-seven million, seven hundred sixty-one thousand, nine hundred seventy-nine".