638693 has 8 divisors (see below), whose sum is σ = 719616. Its totient is φ = 561600.

The previous prime is 638689. The next prime is 638699. The reversal of 638693 is 396836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 638693 - 2² = 638689 is a prime.

It is an Ulam number.

It is a d-powerful number, because it can be written as 6⁷ + 3⁹ + 6⁷ + 8 + 9² + 3¹⁰ .

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638699) 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 7 ways as a sum of consecutive naturals, for example, 596 + ... + 1277.

It is an arithmetic number, because the mean of its divisors is an integer number (89952).

2⁶³⁸⁶⁹³ is an apocalyptic number.

It is an amenable number.

638693 is a deficient number, since it is larger than the sum of its proper divisors (80923).

638693 is a wasteful number, since it uses less digits than its factorization.

638693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1915.

The product of its digits is 23328, while the sum is 35.

The square root of 638693 is about 799.1827075206. The cubic root of 638693 is about 86.1186841607.

It can be divided in two parts, 638 and 693, that added together give a palindrome (1331).

The spelling of 638693 in words is "six hundred thirty-eight thousand, six hundred ninety-three".