638157763 has 2 divisors, whose sum is σ = 638157764. Its totient is φ = 638157762.

The previous prime is 638157761. The next prime is 638157787. The reversal of 638157763 is 367751836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638157763 - 2¹ = 638157761 is a prime.

Together with 638157761, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (638157761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319078881 + 319078882.

It is an arithmetic number, because the mean of its divisors is an integer number (319078882).

Almost surely, 2^638157763 is an apocalyptic number.

638157763 is a deficient number, since it is larger than the sum of its proper divisors (1).

638157763 is an equidigital number, since it uses as much as digits as its factorization.

638157763 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 46.

The square root of 638157763 is about 25261.7846360862. The cubic root of 638157763 is about 860.9462106729.

The spelling of 638157763 in words is "six hundred thirty-eight million, one hundred fifty-seven thousand, seven hundred sixty-three".