638674783927 has 2 divisors, whose sum is σ = 638674783928. Its totient is φ = 638674783926.

The previous prime is 638674783897. The next prime is 638674783937. The reversal of 638674783927 is 729387476836.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638674783927 - 2²³ = 638666395319 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638674783937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319337391963 + 319337391964.

It is an arithmetic number, because the mean of its divisors is an integer number (319337391964).

Almost surely, 2^638674783927 is an apocalyptic number.

638674783927 is a deficient number, since it is larger than the sum of its proper divisors (1).

638674783927 is an equidigital number, since it uses as much as digits as its factorization.

638674783927 is an evil number, because the sum of its binary digits is even.

The product of its digits is 512096256, while the sum is 70.

The spelling of 638674783927 in words is "six hundred thirty-eight billion, six hundred seventy-four million, seven hundred eighty-three thousand, nine hundred twenty-seven".