638351 has 4 divisors (see below), whose sum is σ = 729552. Its totient is φ = 547152.

The previous prime is 638347. The next prime is 638359. The reversal of 638351 is 153836.

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

It is a cyclic number.

It is not a de Polignac number, because 638351 - 2² = 638347 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638351.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638359) 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, 45590 + ... + 45603.

It is an arithmetic number, because the mean of its divisors is an integer number (182388).

2⁶³⁸³⁵¹ is an apocalyptic number.

638351 is a deficient number, since it is larger than the sum of its proper divisors (91201).

638351 is an equidigital number, since it uses as much as digits as its factorization.

638351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91200.

The product of its digits is 2160, while the sum is 26.

The square root of 638351 is about 798.9687102759. The cubic root of 638351 is about 86.1033101346.

It can be divided in two parts, 63835 and 1, that added together give a palindrome (63836).

The spelling of 638351 in words is "six hundred thirty-eight thousand, three hundred fifty-one".