638743 has 4 divisors (see below), whose sum is σ = 730000. Its totient is φ = 547488.

The previous prime is 638719. The next prime is 638767. The reversal of 638743 is 347836.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (638719) and next prime (638767).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638743 is a prime.

It is a d-powerful number, because it can be written as 6² + 3⁸ + 7⁴ + 8⁵ + 4⁸ + 3¹² .

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (632743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45618 + ... + 45631.

It is an arithmetic number, because the mean of its divisors is an integer number (182500).

2⁶³⁸⁷⁴³ is an apocalyptic number.

638743 is a deficient number, since it is larger than the sum of its proper divisors (91257).

638743 is an equidigital number, since it uses as much as digits as its factorization.

638743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91256.

The product of its digits is 12096, while the sum is 31.

The square root of 638743 is about 799.2139888666. The cubic root of 638743 is about 86.1209313655.

The spelling of 638743 in words is "six hundred thirty-eight thousand, seven hundred forty-three".