638914217 has 8 divisors (see below), whose sum is σ = 668416320. Its totient is φ = 609555760.

The previous prime is 638914201. The next prime is 638914219. The reversal of 638914217 is 712419836.

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 638914217 - 2⁴ = 638914201 is a prime.

It is a super-2 number, since 2×638914217² = 816422753369446178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638914219) 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, 26759 + ... + 44652.

It is an arithmetic number, because the mean of its divisors is an integer number (83552040).

Almost surely, 2^638914217 is an apocalyptic number.

It is an amenable number.

638914217 is a deficient number, since it is larger than the sum of its proper divisors (29502103).

638914217 is a wasteful number, since it uses less digits than its factorization.

638914217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71823.

The product of its digits is 72576, while the sum is 41.

The square root of 638914217 is about 25276.7525010631. The cubic root of 638914217 is about 861.2862567039.

The spelling of 638914217 in words is "six hundred thirty-eight million, nine hundred fourteen thousand, two hundred seventeen".