638926 has 8 divisors (see below), whose sum is σ = 968184. Its totient is φ = 316200.

The previous prime is 638923. The next prime is 638933. The reversal of 638926 is 629836.

638926 = 24² + 25² + ... + 124².

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 638891 and 638900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1380 + ... + 1783.

It is an arithmetic number, because the mean of its divisors is an integer number (121023).

2⁶³⁸⁹²⁶ is an apocalyptic number.

638926 is a deficient number, since it is larger than the sum of its proper divisors (329258).

638926 is a wasteful number, since it uses less digits than its factorization.

638926 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3266.

The product of its digits is 15552, while the sum is 34.

The square root of 638926 is about 799.3284681531. The cubic root of 638926 is about 86.1291551350.

The spelling of 638926 in words is "six hundred thirty-eight thousand, nine hundred twenty-six".