638697 has 8 divisors (see below), whose sum is σ = 856480. Its totient is φ = 423360.

The previous prime is 638689. The next prime is 638699. The reversal of 638697 is 796836.

638697 is nontrivially palindromic in base 15.

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

It is not a de Polignac number, because 638697 - 2³ = 638689 is a prime.

It is a Duffinian 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, 129 + ... + 1137.

It is an arithmetic number, because the mean of its divisors is an integer number (107060).

2⁶³⁸⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

638697 is a deficient number, since it is larger than the sum of its proper divisors (217783).

638697 is a wasteful number, since it uses less digits than its factorization.

638697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1223.

The product of its digits is 54432, while the sum is 39.

The square root of 638697 is about 799.1852100734. The cubic root of 638697 is about 86.1188639414.

The spelling of 638697 in words is "six hundred thirty-eight thousand, six hundred ninety-seven".