638767 has 2 divisors, whose sum is σ = 638768. Its totient is φ = 638766.

The previous prime is 638719. The next prime is 638801. The reversal of 638767 is 767836.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 638767 - 2¹¹ = 636719 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (638717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319383 + 319384.

It is an arithmetic number, because the mean of its divisors is an integer number (319384).

2⁶³⁸⁷⁶⁷ is an apocalyptic number.

638767 is a deficient number, since it is larger than the sum of its proper divisors (1).

638767 is an equidigital number, since it uses as much as digits as its factorization.

638767 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 37.

The square root of 638767 is about 799.2290034777. The cubic root of 638767 is about 86.1220099821.

The spelling of 638767 in words is "six hundred thirty-eight thousand, seven hundred sixty-seven".